From 11b0f0dfd77694ecd270cd76fb75dac5b59fbfb7 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 31 Mar 2026 09:51:55 +0200
Subject: [PATCH 01/43] Use slightly longer delays after changing machine in
 #1034.

---
 .github/workflows/build.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index e10620c84..b247fca68 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -113,7 +113,7 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: 8
+          DELAY_FACTOR: 10
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |

From 920448c99cbbd384e001b93ab047747d88925b87 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 31 Mar 2026 11:47:54 +0200
Subject: [PATCH 02/43] Wait longer for call hierarchies.

---
 .github/workflows/build.yaml                              | 2 +-
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index b247fca68..e10620c84 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -113,7 +113,7 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: 10
+          DELAY_FACTOR: 8
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |
diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 83c66c498..6170e7d4c 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -296,7 +296,7 @@ end
             const outgoing = await ignoreFails(new SideBarView().getContent().getSection("Callers Of"));
             const items = await ignoreFails(outgoing!.getVisibleItems());
             return items?.length === 2;
-        }, Delays.normal, "Call hierarchy should show `multiply` and its recursive call.");
+        }, Delays.slow, "Call hierarchy should show `multiply` and its recursive call.");
 
         await editor.selectText("multiply");
         await bench.executeCommand("view.showOutgoingCalls");
@@ -304,7 +304,7 @@ end
             const incoming = await ignoreFails(new SideBarView().getContent().getSection("Calls From"));
             const items = await ignoreFails(incoming!.getVisibleItems());
             return items?.length === 3;
-        }, Delays.normal, "Call hierarchy should show `multiply` and its two outgoing calls.");
+        }, Delays.slow, "Call hierarchy should show `multiply` and its two outgoing calls.");
     });
 
     it("completion works", async function() {

From e7821b7d68294815c317b4e0b2c77be69eb852a2 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 31 Mar 2026 11:48:20 +0200
Subject: [PATCH 03/43] Await rename trigger.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 3 +--
 rascal-vscode-extension/src/test/vscode-suite/ide.test.ts | 3 +--
 rascal-vscode-extension/src/test/vscode-suite/utils.ts    | 1 +
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 6170e7d4c..3db5e6757 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -248,8 +248,7 @@ end
         const editor = await ide.openModule(TestWorkspace.picoFile);
         await editor.moveCursor(5, 6);
 
-        ide.renameSymbol(editor, bench, "z");
-
+        await ide.renameSymbol(editor, bench, "z");
         await driver.wait(() => (editor.isDirty()), Delays.extremelySlow, "Rename should have resulted in changes in the editor");
 
         const editorText = await editor.getText();
diff --git a/rascal-vscode-extension/src/test/vscode-suite/ide.test.ts b/rascal-vscode-extension/src/test/vscode-suite/ide.test.ts
index 0e147389a..cfdb28154 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/ide.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/ide.test.ts
@@ -196,8 +196,7 @@ describe('IDE', function () {
         const checkRascalStatus = ide.statusContains("Loading Rascal");
         await driver.wait(async () => !(await checkRascalStatus()), Delays.extremelySlow, "Rascal evaluators have not finished loading");
 
-        ide.renameSymbol(editor, bench, "i");
-
+        await ide.renameSymbol(editor, bench, "i");
         await driver.wait(() => (editor.isDirty()), Delays.extremelySlow, "Rename should have resulted in changes in the editor");
 
         const editorText = await editor.getText();
diff --git a/rascal-vscode-extension/src/test/vscode-suite/utils.ts b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
index a46aa8c4d..b14df7e3d 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/utils.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
@@ -379,6 +379,7 @@ export class IDEOperations {
             }
             catch (e) {
                 console.log("Rename failed to succeed, lets try again");
+                console.error(e);
                 await this.screenshot(`DSL-failed-rename-round-${tries}`);
                 tries++;
             }

From c731214846878935d93a663526225677656e8460 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 31 Mar 2026 13:17:12 +0200
Subject: [PATCH 04/43] Slightly longer timeouts again.

---
 .github/workflows/build.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index e10620c84..b247fca68 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -113,7 +113,7 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: 8
+          DELAY_FACTOR: 10
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |

From a3e5b407c76b4d7daf1cc353ed00c0cff21731d6 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 1 Apr 2026 17:02:05 +0200
Subject: [PATCH 05/43] Try even longer delay factor.

---
 .github/workflows/build.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index b247fca68..cb2ca5efc 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -113,7 +113,7 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: 10
+          DELAY_FACTOR: 15
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |

From ce4e7b19b8aabab4334c09932ddd453f123da4c8 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Thu, 2 Apr 2026 14:10:05 +0200
Subject: [PATCH 06/43] Try 22.04 with original delays.

---
 .github/workflows/build.yaml | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index cb2ca5efc..4466f794f 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,7 +49,7 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4, windows-latest, macos-latest]
+        os: [ubicloud-standard-4-ubuntu-2204, windows-latest, macos-latest]
       fail-fast: true
     env:
       CODE_VERSION: "1.90.2"
@@ -113,12 +113,10 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: 15
+          DELAY_FACTOR: 8
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
-        run: |
-          sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0 # workaround for issue with Ubuntu 24.04 https://github.com/redhat-developer/vscode-extension-tester/blob/main/KNOWN_ISSUES.md#openresources-not-working-with-apparmor-2404
-          xvfb-run --auto-servernum --server-args='-screen 0 1920x1080x24' npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
+        run: xvfb-run --auto-servernum --server-args='-screen 0 1920x1080x24' npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
 
       - name: Upload Screenshots
         uses: actions/upload-artifact@v7

From 0ec6418537dafcba48964b23e65fe86435fff1fb Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Thu, 2 Apr 2026 16:39:12 +0200
Subject: [PATCH 07/43] Revert test-specific delays.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 3db5e6757..ee09b3783 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -295,7 +295,7 @@ end
             const outgoing = await ignoreFails(new SideBarView().getContent().getSection("Callers Of"));
             const items = await ignoreFails(outgoing!.getVisibleItems());
             return items?.length === 2;
-        }, Delays.slow, "Call hierarchy should show `multiply` and its recursive call.");
+        }, Delays.normal, "Call hierarchy should show `multiply` and its recursive call.");
 
         await editor.selectText("multiply");
         await bench.executeCommand("view.showOutgoingCalls");
@@ -303,7 +303,7 @@ end
             const incoming = await ignoreFails(new SideBarView().getContent().getSection("Calls From"));
             const items = await ignoreFails(incoming!.getVisibleItems());
             return items?.length === 3;
-        }, Delays.slow, "Call hierarchy should show `multiply` and its two outgoing calls.");
+        }, Delays.normal, "Call hierarchy should show `multiply` and its two outgoing calls.");
     });
 
     it("completion works", async function() {

From e047fce30a197640ede6e14e0c53c4a2bba9ec51 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 12:28:01 +0200
Subject: [PATCH 08/43] Revert "Try 22.04 with original delays."

This reverts commit ce4e7b19b8aabab4334c09932ddd453f123da4c8.
---
 .github/workflows/build.yaml | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 4466f794f..cb2ca5efc 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,7 +49,7 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4-ubuntu-2204, windows-latest, macos-latest]
+        os: [ubicloud-standard-4, windows-latest, macos-latest]
       fail-fast: true
     env:
       CODE_VERSION: "1.90.2"
@@ -113,10 +113,12 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: 8
+          DELAY_FACTOR: 15
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
-        run: xvfb-run --auto-servernum --server-args='-screen 0 1920x1080x24' npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
+        run: |
+          sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0 # workaround for issue with Ubuntu 24.04 https://github.com/redhat-developer/vscode-extension-tester/blob/main/KNOWN_ISSUES.md#openresources-not-working-with-apparmor-2404
+          xvfb-run --auto-servernum --server-args='-screen 0 1920x1080x24' npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
 
       - name: Upload Screenshots
         uses: actions/upload-artifact@v7

From 3a627bd686643aa7b59dcab0871cf6d3337f2cd8 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 12:30:40 +0200
Subject: [PATCH 09/43] Try several Ubuntu machines and delays.

---
 .github/workflows/build.yaml | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index cb2ca5efc..6d7b629ab 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,8 +49,10 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4, windows-latest, macos-latest]
-      fail-fast: true
+        os: [ubicloud-standard-4, ubicloud-standard-4-2204, ubuntu-latest]
+        run: [1, 2, 3, 4]
+        delay_factor: [8, 16, 32, 64]
+      fail-fast: false
     env:
       CODE_VERSION: "1.90.2"
     runs-on:  ${{ matrix.os }}
@@ -113,7 +115,7 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: 15
+          DELAY_FACTOR: matrix.delay_factor
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |

From 187cae43c48f31e4952115f4c6717085c6f86b10 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 12:32:45 +0200
Subject: [PATCH 10/43] Check rename state with screenshots.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index ee09b3783..11948c2fb 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -249,7 +249,10 @@ end
         await editor.moveCursor(5, 6);
 
         await ide.renameSymbol(editor, bench, "z");
-        await driver.wait(() => (editor.isDirty()), Delays.extremelySlow, "Rename should have resulted in changes in the editor");
+        await driver.wait(async () => {
+            await ide.screenshot("rename-dirty-check");
+            return editor.isDirty();
+        }, Delays.extremelySlow, "Rename should have resulted in changes in the editor");
 
         const editorText = await editor.getText();
         expect(editorText).to.contain("z : natural");

From e84e27f97d458e8d528975c9807493a339f90bcc Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 14:22:41 +0200
Subject: [PATCH 11/43] Fix runner name, less runs.

---
 .github/workflows/build.yaml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 6d7b629ab..6dddc448d 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,8 +49,7 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4, ubicloud-standard-4-2204, ubuntu-latest]
-        run: [1, 2, 3, 4]
+        os: [ubicloud-standard-4, ubicloud-standard-4-ubuntu-2204, ubuntu-latest]
         delay_factor: [8, 16, 32, 64]
       fail-fast: false
     env:

From 39920fc2a2994d13f7dc12e4de80173127ab1e18 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 14:23:33 +0200
Subject: [PATCH 12/43] Be explicit about GH runner versions.

---
 .github/workflows/build.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 6dddc448d..f23e6634a 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,7 +49,7 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4, ubicloud-standard-4-ubuntu-2204, ubuntu-latest]
+        os: [ubicloud-standard-4, ubicloud-standard-4-ubuntu-2204, ubuntu-22.04, ubuntu-24.04]
         delay_factor: [8, 16, 32, 64]
       fail-fast: false
     env:

From 4ac694948de9557ee02bbd01d3582277e006c9f0 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 15:07:46 +0200
Subject: [PATCH 13/43] Revert extester to 8.22.1

---
 rascal-vscode-extension/package-lock.json | 14 +++++++-------
 rascal-vscode-extension/package.json      |  2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/rascal-vscode-extension/package-lock.json b/rascal-vscode-extension/package-lock.json
index 5c081362d..75b8ad15a 100644
--- a/rascal-vscode-extension/package-lock.json
+++ b/rascal-vscode-extension/package-lock.json
@@ -33,7 +33,7 @@
         "license-check-and-add": "4.x",
         "mocha": "11.x",
         "typescript": "5.x",
-        "vscode-extension-tester": "8.x"
+        "vscode-extension-tester": "8.22.1"
       },
       "engines": {
         "node": ">=20.9.0",
@@ -8799,21 +8799,21 @@
       }
     },
     "node_modules/vscode-extension-tester": {
-      "version": "8.23.0",
-      "resolved": "https://registry.npmjs.org/vscode-extension-tester/-/vscode-extension-tester-8.23.0.tgz",
-      "integrity": "sha512-YElhRDkOjvmGFv44aCMnEnUM5RmFqWByQ8TBr7/6N9K/b5o1gu2fo9EgTef6VmrB4kyFnSrkPVAbiZBfKQA1mQ==",
+      "version": "8.22.1",
+      "resolved": "https://registry.npmjs.org/vscode-extension-tester/-/vscode-extension-tester-8.22.1.tgz",
+      "integrity": "sha512-euqibuaeGaQofejTKZqfHNkGSz+dmcuS687PROWjj01k48xm0XVbqc6WKpIzSRob3vYx3npy+8pFZ1dVRaW7Hw==",
       "dev": true,
       "license": "Apache-2.0",
       "dependencies": {
-        "@redhat-developer/locators": "^1.20.0",
-        "@redhat-developer/page-objects": "^1.20.0",
+        "@redhat-developer/locators": "^1.19.1",
+        "@redhat-developer/page-objects": "^1.19.1",
         "@types/selenium-webdriver": "^4.35.5",
         "@vscode/vsce": "^3.7.1",
         "c8": "^11.0.0",
         "commander": "^14.0.3",
         "compare-versions": "^6.1.1",
         "find-up": "8.0.0",
-        "fs-extra": "^11.3.4",
+        "fs-extra": "^11.3.3",
         "glob": "^13.0.6",
         "got": "^14.6.6",
         "hpagent": "^1.2.0",
diff --git a/rascal-vscode-extension/package.json b/rascal-vscode-extension/package.json
index e20276f32..ccf386a6e 100644
--- a/rascal-vscode-extension/package.json
+++ b/rascal-vscode-extension/package.json
@@ -329,6 +329,6 @@
     "license-check-and-add": "4.x",
     "mocha": "11.x",
     "typescript": "5.x",
-    "vscode-extension-tester": "8.x"
+    "vscode-extension-tester": "8.22.1"
   }
 }

From 99b1ec78110380f57ef016338ddad4110cc04fa7 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 15:32:10 +0200
Subject: [PATCH 14/43] Debug test initialization.

---
 .../src/test/vscode-suite/dsl.test.ts                  |  9 ++++++++-
 rascal-vscode-extension/src/test/vscode-suite/utils.ts | 10 +++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 11948c2fb..dfed50eeb 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -76,15 +76,22 @@ parameterizedDescribe(function (errorRecovery: boolean) {
     }
 
     before(async () => {
+        console.log("Initializing browser");
         browser = VSBrowser.instance;
+        console.log("Initializing driver");
         driver = browser.driver;
+        console.log("Initializing workbench");
         bench = new Workbench();
+        console.log("Waiting for worbench");
         await ignoreFails(browser.waitForWorkbench());
+        console.log("Initializing IDE operations");
         ide = new IDEOperations(browser);
+        console.log("Loading IDE");
         await ide.load();
+        console.log("Loading Pico");
         await loadPico();
+        console.log("Reading backup file");
         picoFileBackup = await fs.readFile(TestWorkspace.picoFile);
-        ide = new IDEOperations(browser);
         await ide.load();
     });
 
diff --git a/rascal-vscode-extension/src/test/vscode-suite/utils.ts b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
index b14df7e3d..78db13f47 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/utils.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
@@ -211,6 +211,7 @@ export class IDEOperations {
     }
 
     async load() {
+        console.log("Loading IDE...");
         await ignoreFails(this.browser.waitForWorkbench(Delays.slow));
         for (let t = 0; t < 5; t++) {
             try {
@@ -218,16 +219,23 @@ export class IDEOperations {
                 if (isWorkSpaceOpen !== undefined && isWorkSpaceOpen.length > 0) {
                     break;
                 }
+                console.log(`Opening workspace ${TestWorkspace.workspaceFile}`);
                 await this.browser.openResources(TestWorkspace.workspaceFile);
             } catch (ex) {
-                console.debug("Error opening workspace, retrying.", ex);
+                console.error("Error opening workspace, retrying.", ex);
             }
         }
+        console.log("Waiting for workbench");
         await ignoreFails(this.browser.waitForWorkbench(Delays.normal));
+        console.log("Waiting for workbench again");
         await ignoreFails(this.browser.waitForWorkbench(Delays.normal));
+        console.log("Opening notifications center");
         const center = await ignoreFails(new Workbench().openNotificationsCenter());
+        console.log("Clearing all notifications");
         await ignoreFails(center?.clearAllNotifications());
+        console.log("Closing notifications center");
         await ignoreFails(center?.close());
+        console.log("Assuring debug level logging is enabled");
         await assureDebugLevelLoggingIsEnabled();
     }
 

From 7d4dcc12c5bfed203dac92c85799923d429d8cf2 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 15:45:30 +0200
Subject: [PATCH 15/43] More logging.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 4 ++++
 rascal-vscode-extension/src/test/vscode-suite/utils.ts    | 1 +
 2 files changed, 5 insertions(+)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index dfed50eeb..2409d94c6 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -96,17 +96,21 @@ parameterizedDescribe(function (errorRecovery: boolean) {
     });
 
     beforeEach(async function () {
+        console.log(`[begin] beforeEach(${this.test?.title})`);
         if (this.test?.title) {
             await ide.screenshot(`DSL-${errorRecovery}-` + this.test?.title);
         }
+        console.log(`[end] beforeEach(${this.test?.title})`);
     });
 
     afterEach(async function () {
+        console.log(`[begin] afterEach(${this.test?.title})`);
         if (this.test?.title) {
             await ide.screenshot(`DSL-${errorRecovery}-`+ this.test?.title);
         }
         await ide.cleanup();
         await fs.writeFile(TestWorkspace.picoFile, picoFileBackup);
+        console.log(`[end] afterEach(${this.test?.title})`);
     });
 
     it("has highlighting and parse errors", async function () {
diff --git a/rascal-vscode-extension/src/test/vscode-suite/utils.ts b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
index 78db13f47..6423833ce 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/utils.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
@@ -457,6 +457,7 @@ export class IDEOperations {
     private screenshotSeqNumber = 0;
 
     screenshot(name: string): Promise<void> {
+        console.log(`Taking screenshot ${name}`);
         return this.browser.takeScreenshot(
             `${String(this.screenshotSeqNumber++).padStart(4, '0')}-` + // Make sorting screenshots chronologically in VS Code easier
             name.replace(/[/\\?%*:|"<>]/g, '-'));

From baf5f03be51423945e8bac2d77359c6f26dadaa1 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 15:45:41 +0200
Subject: [PATCH 16/43] Run single machine for now.

---
 .github/workflows/build.yaml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index f23e6634a..a9932e750 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,8 +49,8 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4, ubicloud-standard-4-ubuntu-2204, ubuntu-22.04, ubuntu-24.04]
-        delay_factor: [8, 16, 32, 64]
+        os: [ubicloud-standard-4] #, ubicloud-standard-4-ubuntu-2204, ubuntu-22.04, ubuntu-24.04]
+        delay_factor: [8] #, 16, 32, 64]
       fail-fast: false
     env:
       CODE_VERSION: "1.90.2"

From fb30dbd241edd3a55e0a32b9a6c9a0312fb942d1 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 16:42:32 +0200
Subject: [PATCH 17/43] Log within first test.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 2409d94c6..75da61904 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -114,13 +114,18 @@ parameterizedDescribe(function (errorRecovery: boolean) {
     });
 
     it("has highlighting and parse errors", async function () {
+        console.log("Closing all editors");
         await ignoreFails(new Workbench().getEditorView().closeAllEditors());
+        console.log(`Opening Pico file ${TestWorkspace.picoFile}`);
         const editor = await ide.openModule(TestWorkspace.picoFile);
         const isPicoLoading = ide.statusContains("Pico");
         // we might miss this event, but we wait for it to show up
+        console.log("Awaiting Pico parser generator start");
         await ignoreFails(driver.wait(isPicoLoading, Delays.normal, "Pico parser generator should have started"));
         // now wait for the Pico parser generator to disappear
+        console.log("Awaiting Pico parser generator finish");
         await driver.wait(async () => !(await isPicoLoading()), Delays.verySlow, "Pico parser generator should have finished", 100);
+        console.log("hHas syntax highilighting?");
         await ide.hasSyntaxHighlighting(editor, Delays.slow);
         console.log("We got syntax highlighting");
         try {

From c74642d07f53f3bddfcef0fd703c6998d46f1a57 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Wed, 8 Apr 2026 16:51:15 +0200
Subject: [PATCH 18/43] Screenshot and loading check changes.

---
 .../src/test/vscode-suite/dsl.test.ts              | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 75da61904..793802ad0 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -120,11 +120,17 @@ parameterizedDescribe(function (errorRecovery: boolean) {
         const editor = await ide.openModule(TestWorkspace.picoFile);
         const isPicoLoading = ide.statusContains("Pico");
         // we might miss this event, but we wait for it to show up
-        console.log("Awaiting Pico parser generator start");
-        await ignoreFails(driver.wait(isPicoLoading, Delays.normal, "Pico parser generator should have started"));
+        await ignoreFails(driver.wait(async () => {
+            console.log("Awaiting Pico parser generator start");
+            await ide.screenshot("is-pico-loading");
+            return await isPicoLoading();
+        }, Delays.normal, "Pico parser generator should have started"));
         // now wait for the Pico parser generator to disappear
-        console.log("Awaiting Pico parser generator finish");
-        await driver.wait(async () => !(await isPicoLoading()), Delays.verySlow, "Pico parser generator should have finished", 100);
+        await driver.wait(async () => {
+            console.log("Awaiting Pico parser generator finish");
+            await ide.screenshot("is-pico-loading-finished");
+            return !(await isPicoLoading());
+        }, Delays.verySlow, "Pico parser generator should have finished", 100);
         console.log("hHas syntax highilighting?");
         await ide.hasSyntaxHighlighting(editor, Delays.slow);
         console.log("We got syntax highlighting");

From cecc26c79f7484787140a01121e4bad4c2f1365b Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Thu, 9 Apr 2026 08:58:56 +0200
Subject: [PATCH 19/43] Also upload screenshots on cancellation.

---
 .github/workflows/build.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index a9932e750..0dd114054 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -123,7 +123,7 @@ jobs:
 
       - name: Upload Screenshots
         uses: actions/upload-artifact@v7
-        if: failure()
+        if: failure() || cancelled()
         with:
           name: screenshots-${{ matrix.os }}
           path: ./rascal-vscode-extension/uitests/screenshots/**/*.png

From ed4311c59ffd22e4a86dd691792097f30f4d2876 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Thu, 9 Apr 2026 09:04:34 +0200
Subject: [PATCH 20/43] Additional screenshot.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 793802ad0..167050856 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -118,6 +118,7 @@ parameterizedDescribe(function (errorRecovery: boolean) {
         await ignoreFails(new Workbench().getEditorView().closeAllEditors());
         console.log(`Opening Pico file ${TestWorkspace.picoFile}`);
         const editor = await ide.openModule(TestWorkspace.picoFile);
+        await ide.screenshot("after-opening-pico-file");
         const isPicoLoading = ide.statusContains("Pico");
         // we might miss this event, but we wait for it to show up
         await ignoreFails(driver.wait(async () => {

From 2c789a594f8cc533a19e93540d2faf8863e37228 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Thu, 9 Apr 2026 10:28:28 +0200
Subject: [PATCH 21/43] Revert loading check, more screenshots.

---
 .github/workflows/build.yaml                              | 2 +-
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 8 ++------
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 0dd114054..1eddb6a7e 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -114,7 +114,7 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: matrix.delay_factor
+          DELAY_FACTOR: 8
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |
diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 167050856..2804ee31d 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -92,7 +92,7 @@ parameterizedDescribe(function (errorRecovery: boolean) {
         await loadPico();
         console.log("Reading backup file");
         picoFileBackup = await fs.readFile(TestWorkspace.picoFile);
-        await ide.load();
+        await ide.screenshot("after [before] init");
     });
 
     beforeEach(async function () {
@@ -121,11 +121,7 @@ parameterizedDescribe(function (errorRecovery: boolean) {
         await ide.screenshot("after-opening-pico-file");
         const isPicoLoading = ide.statusContains("Pico");
         // we might miss this event, but we wait for it to show up
-        await ignoreFails(driver.wait(async () => {
-            console.log("Awaiting Pico parser generator start");
-            await ide.screenshot("is-pico-loading");
-            return await isPicoLoading();
-        }, Delays.normal, "Pico parser generator should have started"));
+        await ignoreFails(driver.wait(isPicoLoading, Delays.normal, "Pico parser generator should have started"));
         // now wait for the Pico parser generator to disappear
         await driver.wait(async () => {
             console.log("Awaiting Pico parser generator finish");

From 533252b343054698e5c7b924d2ff4a6d45178ec3 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Thu, 9 Apr 2026 10:45:32 +0200
Subject: [PATCH 22/43] Extend matrix again.

---
 .github/workflows/build.yaml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 1eddb6a7e..8d1a1ae4a 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,8 +49,8 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4] #, ubicloud-standard-4-ubuntu-2204, ubuntu-22.04, ubuntu-24.04]
-        delay_factor: [8] #, 16, 32, 64]
+        os: [ubicloud-standard-4, ubicloud-standard-4-ubuntu-2204, ubuntu-22.04, ubuntu-24.04]
+        run: [1, 2, 3, 4]
       fail-fast: false
     env:
       CODE_VERSION: "1.90.2"

From 49c55f2cc5f38504be7db2fb39c6c65f21c74571 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Fri, 10 Apr 2026 09:20:21 +0200
Subject: [PATCH 23/43] Narrow down failing rename test.

---
 .github/workflows/build.yaml                           | 10 +++++-----
 rascal-vscode-extension/src/test/vscode-suite/utils.ts |  1 +
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 8d1a1ae4a..d188db9e8 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,8 +49,8 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4, ubicloud-standard-4-ubuntu-2204, ubuntu-22.04, ubuntu-24.04]
-        run: [1, 2, 3, 4]
+        os: [ubicloud-standard-4, ubicloud-standard-4-ubuntu-2204]
+        run: [1, 2, 3, 4, 5, 6, 7, 8]
       fail-fast: false
     env:
       CODE_VERSION: "1.90.2"
@@ -97,7 +97,7 @@ jobs:
           DELAY_FACTOR: 10
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G'
-        run: npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
+        run: npx extest setup-and-run out/test/vscode-suite/dsl.test.js --storage uitests
 
       - name: "UI test (mac)"
         shell: bash
@@ -107,7 +107,7 @@ jobs:
           DELAY_FACTOR: 15
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G'
-        run: npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
+        run: npx extest setup-and-run out/test/vscode-suite/dsl.test.js --storage uitests
 
       - name: "UI test (ubuntu)"
         shell: bash
@@ -119,7 +119,7 @@ jobs:
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |
           sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0 # workaround for issue with Ubuntu 24.04 https://github.com/redhat-developer/vscode-extension-tester/blob/main/KNOWN_ISSUES.md#openresources-not-working-with-apparmor-2404
-          xvfb-run --auto-servernum --server-args='-screen 0 1920x1080x24' npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
+          xvfb-run --auto-servernum --server-args='-screen 0 1920x1080x24' npx extest setup-and-run out/test/vscode-suite/dsl.test.js --storage uitests
 
       - name: Upload Screenshots
         uses: actions/upload-artifact@v7
diff --git a/rascal-vscode-extension/src/test/vscode-suite/utils.ts b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
index 6423833ce..6880a49ed 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/utils.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
@@ -384,6 +384,7 @@ export class IDEOperations {
                 const renameBox = await this.hasElement(editor, By.className("rename-input"), Delays.normal, "Rename box should appear");
                 await renameBox.sendKeys(Key.BACK_SPACE, Key.BACK_SPACE, Key.BACK_SPACE, newName, Key.ENTER);
                 renameSuccess = true;
+                console.log("Entering rename name succeeded");
             }
             catch (e) {
                 console.log("Rename failed to succeed, lets try again");

From c1e3a8edb5701b60011bf41010bf11f5b75218c5 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Fri, 10 Apr 2026 09:47:53 +0200
Subject: [PATCH 24/43] Try to fix stale code lens element.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 2804ee31d..de2eba94d 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -241,8 +241,10 @@ end
     it("code lens works", async function() {
         if (errorRecovery) { this.skip(); }
         const editor = await ide.openModule(TestWorkspace.picoFile);
-        const lens = await driver.wait(() => editor.getCodeLens("Rename variables a to b."), Delays.verySlow, "Rename lens should be available");
-        await lens!.click();
+        await driver.wait(async () => {
+            const lens = await editor.getCodeLens("Rename variables a to b.");
+            await ignoreFails(lens!.click());
+        }, Delays.verySlow, "Rename lens should be available");
         await ide.assertLineBecomes(editor, 9, "b := 2;", "a variable should be changed to b");
     });
 

From 277765985e64b0d260cdd10bcb42f7e4ceeaf31e Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Fri, 10 Apr 2026 09:49:12 +0200
Subject: [PATCH 25/43] Unique artifact name.

---
 .github/workflows/build.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index d188db9e8..a0e3d516a 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -125,7 +125,7 @@ jobs:
         uses: actions/upload-artifact@v7
         if: failure() || cancelled()
         with:
-          name: screenshots-${{ matrix.os }}
+          name: screenshots-${{ matrix.os }}-${{matrix.run}}
           path: ./rascal-vscode-extension/uitests/screenshots/**/*.png
           retention-days: 5
           if-no-files-found: error

From 926c45f7ca4ca08e9bec19fbc1e486b14b9e0f5f Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Fri, 10 Apr 2026 10:31:59 +0200
Subject: [PATCH 26/43] Try to fix code lens test again.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index de2eba94d..9c73c4af7 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -243,7 +243,12 @@ end
         const editor = await ide.openModule(TestWorkspace.picoFile);
         await driver.wait(async () => {
             const lens = await editor.getCodeLens("Rename variables a to b.");
-            await ignoreFails(lens!.click());
+            try {
+                await lens!.click();
+                return true;
+            } catch (e) {
+                return false;
+            }
         }, Delays.verySlow, "Rename lens should be available");
         await ide.assertLineBecomes(editor, 9, "b := 2;", "a variable should be changed to b");
     });

From 6c16fa1931b255b96838e102e7c0ddd78358a6c9 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Fri, 10 Apr 2026 11:43:54 +0200
Subject: [PATCH 27/43] Inspect call hierarchy test.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index 9c73c4af7..e2eb7d5f4 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -323,6 +323,7 @@ end
         await driver.wait(async () => {
             const outgoing = await ignoreFails(new SideBarView().getContent().getSection("Callers Of"));
             const items = await ignoreFails(outgoing!.getVisibleItems());
+            await ide.screenshot("call-hierarchy-incoming");
             return items?.length === 2;
         }, Delays.normal, "Call hierarchy should show `multiply` and its recursive call.");
 
@@ -331,6 +332,7 @@ end
         await driver.wait(async () => {
             const incoming = await ignoreFails(new SideBarView().getContent().getSection("Calls From"));
             const items = await ignoreFails(incoming!.getVisibleItems());
+            await ide.screenshot("call-hierarchy-outgoing");
             return items?.length === 3;
         }, Delays.normal, "Call hierarchy should show `multiply` and its two outgoing calls.");
     });

From cd5e7050a7a348e7df5ed9b2a2e917b253e01261 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Fri, 10 Apr 2026 11:44:04 +0200
Subject: [PATCH 28/43] Run 24.04 only.

---
 .github/workflows/build.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index a0e3d516a..f54283109 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -49,7 +49,7 @@ jobs:
   ui-test:
     strategy:
       matrix:
-        os: [ubicloud-standard-4, ubicloud-standard-4-ubuntu-2204]
+        os: [ubicloud-standard-4]
         run: [1, 2, 3, 4, 5, 6, 7, 8]
       fail-fast: false
     env:

From 93845b1005749fe9f6a13792b84c08cb9f6b01b2 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Fri, 10 Apr 2026 11:53:47 +0200
Subject: [PATCH 29/43] Run all tests again.

---
 .github/workflows/build.yaml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index f54283109..c418daa24 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -97,7 +97,7 @@ jobs:
           DELAY_FACTOR: 10
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G'
-        run: npx extest setup-and-run out/test/vscode-suite/dsl.test.js --storage uitests
+        run: npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
 
       - name: "UI test (mac)"
         shell: bash
@@ -107,7 +107,7 @@ jobs:
           DELAY_FACTOR: 15
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G'
-        run: npx extest setup-and-run out/test/vscode-suite/dsl.test.js --storage uitests
+        run: npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
 
       - name: "UI test (ubuntu)"
         shell: bash
@@ -119,7 +119,7 @@ jobs:
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |
           sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0 # workaround for issue with Ubuntu 24.04 https://github.com/redhat-developer/vscode-extension-tester/blob/main/KNOWN_ISSUES.md#openresources-not-working-with-apparmor-2404
-          xvfb-run --auto-servernum --server-args='-screen 0 1920x1080x24' npx extest setup-and-run out/test/vscode-suite/dsl.test.js --storage uitests
+          xvfb-run --auto-servernum --server-args='-screen 0 1920x1080x24' npx extest setup-and-run out/test/vscode-suite/*.test.js --storage uitests
 
       - name: Upload Screenshots
         uses: actions/upload-artifact@v7

From ab1a6b09233878d250d587bb934eb5656aad1c3a Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Mon, 13 Apr 2026 10:03:09 +0200
Subject: [PATCH 30/43] Longer delay factor again.

---
 .github/workflows/build.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index c418daa24..31633c899 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -114,7 +114,7 @@ jobs:
         if: contains(matrix.os, 'ubuntu') || startsWith(matrix.os, 'ubicloud-standard')
         working-directory: ./rascal-vscode-extension
         env:
-          DELAY_FACTOR: 8
+          DELAY_FACTOR: 15
           RASCAL_LSP_DEV_DEPLOY: true
           _JAVA_OPTIONS: '-Xmx5G' # we have 16gb of memory, make sure LSP, REPL & DSL-LSP can start
         run: |

From 6bdfa978998ea4b1334671717cb6859ecce4149d Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Mon, 13 Apr 2026 11:24:50 +0200
Subject: [PATCH 31/43] Debug missing parse tree/contributions.

---
 .../lsp/parametric/ParametricTextDocumentService.java    | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
index c024c43ee..b534891fb 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
@@ -421,7 +421,7 @@ private void handleParsingErrors(TextDocumentState file, CompletableFuture<Versi
                 .map(diagnostic -> diagnostic.instantiate(columns))
                 .collect(Collectors.toList());
 
-            logger.trace("Finished parsing tree, reporting new parse errors: {} for: {}", parseErrors, file.getLocation());
+            logger.info("Finished parsing tree, reporting new parse errors: {} for: {}", parseErrors, file.getLocation());
             facts(file.getLocation()).reportParseErrors(file.getLocation(), diagnostics.version(), parseErrors);
         });
     }
@@ -694,7 +694,10 @@ private ILanguageContributions contributions(ISourceLocation doc) {
             .map(contributions::get)
             .map(ILanguageContributions.class::cast)
             .flatMap(Optional::ofNullable)
-            .orElseGet(() -> new NoContributions(extension(doc), exec));
+            .orElseGet(() -> {
+                logger.error("No contributions for {}", doc);
+                return new NoContributions(extension(doc), exec);
+            });
     }
 
     private static String extension(ISourceLocation doc) {
@@ -1042,7 +1045,7 @@ public Set<String> fileExtensions() {
 
     private void updateFileState(LanguageParameter lang, ISourceLocation f) {
         f = f.top();
-        logger.trace("File of language {} - updating state: {}", lang.getName(), f);
+        logger.info("File of language {} - updating state: {}", lang.getName(), f);
         // Since we cannot know what happened to this file before we were called, we need to be careful about races.
         // It might have been closed in the meantime, so we compute the new value if the key still exists, based on the current value.
         var state = files.computeIfPresent(f, (loc, currentState) -> currentState.changeParser(contributions(loc)::parsing));

From ed5d656af636b93b977820b06041f1923852bf1b Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 14 Apr 2026 13:37:34 +0200
Subject: [PATCH 32/43] Unwrap NoContributionException.

---
 .../main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java   | 2 +-
 .../org/rascalmpl/vscode/lsp/parametric/NoContributions.java    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
index 89f889fe5..11b6611f0 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
@@ -132,7 +132,7 @@ public CompletableFuture<Versioned<ITree>> getCurrentTreeAsync(boolean allowReco
     }
 
     /**
-     * Wait for current tree to parse. Then return the last tree that matches the allowRecoveredErrors conditation.
+     * Wait for current tree to parse. Then return the last tree that matches the allowRecoveredErrors condition.
      * @param allowRecoveredErrors if false, the result will not contain a tree with recovered errors.
      * @return the last parse tree, or an exception if non existed.
      */
diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/NoContributions.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/NoContributions.java
index b30c31360..d8b999f2a 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/NoContributions.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/NoContributions.java
@@ -87,7 +87,7 @@ public String getName() {
 
     @Override
     public CompletableFuture<ITree> parsing(ISourceLocation loc, String input) {
-        return CompletableFuture.failedFuture(new NoContributionException("parsing"));
+        throw new NoContributionException("parsing");
     }
 
     @Override

From 6729b09220ab84f5343ab714f417ac05cdf2e34f Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 14 Apr 2026 13:54:02 +0200
Subject: [PATCH 33/43] Include problems in screenshot.

---
 rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
index e2eb7d5f4..f55761fd2 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/dsl.test.ts
@@ -106,6 +106,8 @@ parameterizedDescribe(function (errorRecovery: boolean) {
     afterEach(async function () {
         console.log(`[begin] afterEach(${this.test?.title})`);
         if (this.test?.title) {
+            const bb = await new Workbench().getBottomBar();
+            await bb.openProblemsView();
             await ide.screenshot(`DSL-${errorRecovery}-`+ this.test?.title);
         }
         await ide.cleanup();

From 67c3d6ff6abc93201f41b8d54ac0451d7e4a1d00 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 14 Apr 2026 14:32:46 +0200
Subject: [PATCH 34/43] Debug stale diagnostics.

---
 .../vscode/lsp/parametric/ParametricTextDocumentService.java   | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
index b534891fb..ee6b3073f 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
@@ -360,6 +360,7 @@ public void didClose(DidCloseTextDocumentParams params) {
         logger.debug("Did Close file: {}", params.getTextDocument());
         var loc = Locations.toLoc(params.getTextDocument());
         if (files.remove(loc) == null) {
+            logger.error("Received `didClose` for unknown file: {}", loc);
             throw new ResponseErrorException(unknownFileError(loc, params));
         }
         facts(loc).close(loc);
@@ -372,9 +373,11 @@ public void didClose(DidCloseTextDocumentParams params) {
 
     @Override
     public void didDeleteFiles(DeleteFilesParams params) {
+        logger.debug("textDocument/didDeleteFiles({})", params);
         exec.submit(() -> {
             // if a file is deleted, and we were tracking it, we remove our diagnostics
             for (var f : params.getFiles()) {
+                logger.debug("Received `didDelete` for {}", f);
                 availableClient().publishDiagnostics(new PublishDiagnosticsParams(f.getUri(), List.of()));
             }
         });

From a423f25a852d1477fbf2ce1918af5e2325f56adc Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 14 Apr 2026 14:34:16 +0200
Subject: [PATCH 35/43] Await screenshots.

---
 rascal-vscode-extension/src/test/vscode-suite/utils.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rascal-vscode-extension/src/test/vscode-suite/utils.ts b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
index 6880a49ed..57505a89b 100644
--- a/rascal-vscode-extension/src/test/vscode-suite/utils.ts
+++ b/rascal-vscode-extension/src/test/vscode-suite/utils.ts
@@ -291,7 +291,7 @@ export class IDEOperations {
                 await new Workbench().executeCommand("workbench.action.revertAndCloseActiveEditor");
             } catch (ex) {
                 const title = ignoreFails(new TextEditor().getTitle()) ?? 'unknown';
-                this.screenshot(`revert of ${title} failed ` + tryCount);
+                await this.screenshot(`revert of ${title} failed ` + tryCount);
                 console.log(`Revert of ${title} failed, but we ignore it`, ex);
             }
             try {
@@ -307,7 +307,7 @@ export class IDEOperations {
                 return !(await new TextEditor().isDirty());
             }
             catch (ignored) {
-                this.screenshot("open editor check failed " + tryCount);
+                await this.screenshot("open editor check failed " + tryCount);
                 console.log("Open editor dirty check failed: ", ignored);
                 return false;
 

From 0499428a93fc6e4804ff23ae2422fc7c12786adb Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 14 Apr 2026 14:38:35 +0200
Subject: [PATCH 36/43] Log parse events.

---
 .../java/org/rascalmpl/vscode/lsp/TextDocumentState.java     | 5 +++++
 .../org/rascalmpl/vscode/lsp/parametric/NoContributions.java | 1 +
 2 files changed, 6 insertions(+)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
index 11b6611f0..f41c1fadc 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
@@ -198,6 +198,7 @@ public CompletableFuture<Versioned<List<Diagnostics.Template>>> getDiagnosticsAs
         }
 
         private void parse() {
+            logger.debug("Triggering parse for {}", location);
             try {
                 parser.apply(location, content)
                     .whenComplete((ITree t, Throwable e) -> {
@@ -208,13 +209,17 @@ private void parse() {
 
                         // Complete future to get the tree
                         if (t == null) {
+                            logger.error("Parse completed exceptionally: {}", location);
                             treeAsync.completeExceptionally(e);
                         } else {
                             var tree = new Versioned<>(version, t, timestamp);
+                            logger.error("Parse completed: {}", location);
                             Versioned.replaceIfNewer(last, tree);
                             if (diagnosticsList.isEmpty()) {
+                                logger.error("Parse completed without errors: {}", location);
                                 Versioned.replaceIfNewer(lastWithoutErrors, tree);
                             }
+                            logger.error("TreeAsync completed: {}", location);
                             treeAsync.complete(tree);
                         }
 
diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/NoContributions.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/NoContributions.java
index d8b999f2a..5b209a9a6 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/NoContributions.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/NoContributions.java
@@ -87,6 +87,7 @@ public String getName() {
 
     @Override
     public CompletableFuture<ITree> parsing(ISourceLocation loc, String input) {
+        logger.error("NoContributions::parsing()", loc);
         throw new NoContributionException("parsing");
     }
 

From 706bbdc6bdedfbff1c69e1c6f313c1b017394395 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 14 Apr 2026 17:57:33 +0200
Subject: [PATCH 37/43] Try to find race in Versioned.

---
 .../rascalmpl/vscode/lsp/util/Versioned.java    | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
index 7e8aac0de..7b3c2f430 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
@@ -27,9 +27,14 @@
 package org.rascalmpl.vscode.lsp.util;
 
 import java.util.concurrent.atomic.AtomicReference;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.checkerframework.checker.nullness.qual.PolyNull;
 
 public class Versioned<T> {
+
+    private static final Logger logger = LogManager.getLogger(Versioned.class);
+
     private final int version;
     private final T object;
     private final long timestamp;
@@ -66,13 +71,23 @@ public static <T> AtomicReference<Versioned<T>> atomic(int version, T object) {
     }
 
     public static <T> boolean replaceIfNewer(AtomicReference<@PolyNull Versioned<T>> current, Versioned<T> maybeNewer) {
+        logger.debug("Versioned.replaceIfNewer({}, {})", current, maybeNewer);
         while (true) {
             var old = current.get();
-            if (old == null || old.version() < maybeNewer.version()) {
+            if (old == null) {
+                logger.debug("old == null");
+                if (current.compareAndSet(old, maybeNewer)) {
+                    return true;
+                }
+            } else if (old.version() < maybeNewer.version()) {
+                logger.debug("old version ({}) < new version ({})", old.version, maybeNewer.version);
                 if (current.compareAndSet(old, maybeNewer)) {
                     return true;
+                } else {
+                    logger.debug("compareAndSet failed: {}, {}", current, old);
                 }
             } else {
+                logger.debug("old version ({}) >= new version ({})", old.version, maybeNewer.version);
                 return false;
             }
         }

From 759a0e5f15e51c7b853aed3ec09f33edd3ac9360 Mon Sep 17 00:00:00 2001
From: Toine Hartman <toine.hartman@swat.engineering>
Date: Tue, 14 Apr 2026 18:00:39 +0200
Subject: [PATCH 38/43] Always parse on worker pool.

---
 .../org/rascalmpl/vscode/lsp/TextDocumentState.java  | 12 ++++++++----
 .../parametric/ParametricTextDocumentService.java    |  2 +-
 .../vscode/lsp/rascal/RascalTextDocumentService.java |  2 +-
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
index f41c1fadc..7a27ef5c7 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
@@ -30,6 +30,7 @@
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.BiFunction;
@@ -62,6 +63,7 @@ public class TextDocumentState {
 
     private final BiFunction<ISourceLocation, String, CompletableFuture<ITree>> parser;
     private final ISourceLocation location;
+    private final ExecutorService exec;
 
     private final AtomicReference<Versioned<Update>> current;
     private final AtomicReference<@Nullable Versioned<ITree>> lastWithoutErrors;
@@ -70,10 +72,12 @@ public class TextDocumentState {
     public TextDocumentState(
             BiFunction<ISourceLocation, String, CompletableFuture<ITree>> parser,
             ISourceLocation location,
-            int initialVersion, String initialContent, long initialTimestamp) {
+            int initialVersion, String initialContent, long initialTimestamp,
+            ExecutorService exec) {
 
         this.parser = parser;
         this.location = location;
+        this.exec = exec;
 
         var u = new Update(initialVersion, initialContent, initialTimestamp);
         this.current = new AtomicReference<>(new Versioned<>(initialVersion, u));
@@ -201,7 +205,7 @@ private void parse() {
             logger.debug("Triggering parse for {}", location);
             try {
                 parser.apply(location, content)
-                    .whenComplete((ITree t, Throwable e) -> {
+                    .whenCompleteAsync((ITree t, Throwable e) -> {
                         if (e instanceof CompletionException && e.getCause() != null) {
                             e = e.getCause();
                         }
@@ -226,7 +230,7 @@ private void parse() {
                         // Complete future to get diagnostics
                         var diagnostics = new Versioned<>(version, diagnosticsList);
                         diagnosticsAsync.complete(diagnostics);
-                    });
+                    }, exec);
             } catch (NoContributionException e) {
                 logger.debug("Ignoring missing parser for {}", location, e);
                 treeAsync.completeOnTimeout(new Versioned<>(version, IRascalValueFactory.getInstance().character(0), timestamp), 60, TimeUnit.SECONDS);
@@ -260,6 +264,6 @@ public long getLastModified() {
 
     public TextDocumentState changeParser(BiFunction<ISourceLocation, String, CompletableFuture<ITree>> parsing) {
         var c = getCurrentContent();
-        return new TextDocumentState(parsing, this.location, c.version(), c.get(), getLastModified());
+        return new TextDocumentState(parsing, this.location, c.version(), c.get(), getLastModified(), exec);
     }
 }
diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
index ee6b3073f..a341f6e9f 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
@@ -719,7 +719,7 @@ private ParametricFileFacts facts(ISourceLocation doc) {
 
     private TextDocumentState open(TextDocumentItem doc, long timestamp) {
         return files.computeIfAbsent(Locations.toLoc(doc),
-            l -> new TextDocumentState(contributions(l)::parsing, l, doc.getVersion(), doc.getText(), timestamp));
+            l -> new TextDocumentState(contributions(l)::parsing, l, doc.getVersion(), doc.getText(), timestamp, exec));
     }
 
     private TextDocumentState getFile(ISourceLocation loc) {
diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/rascal/RascalTextDocumentService.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/rascal/RascalTextDocumentService.java
index e581a3273..a13d62b58 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/rascal/RascalTextDocumentService.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/rascal/RascalTextDocumentService.java
@@ -557,7 +557,7 @@ private static <T> T last(List<T> l) {
 
     private TextDocumentState open(TextDocumentItem doc, long timestamp) {
         return documents.computeIfAbsent(Locations.toLoc(doc),
-            l -> new TextDocumentState(availableRascalServices()::parseSourceFile, l, doc.getVersion(), doc.getText(), timestamp));
+            l -> new TextDocumentState(availableRascalServices()::parseSourceFile, l, doc.getVersion(), doc.getText(), timestamp, exec));
     }
 
     private TextDocumentState getFile(TextDocumentIdentifier doc) {

From 58d5ece1575bf315ea371a4e8bf9bc93126e2416 Mon Sep 17 00:00:00 2001
From: Sung-Shik Jongmans <sung-shik.jongmans@swat.engineering>
Date: Wed, 15 Apr 2026 07:42:57 +0200
Subject: [PATCH 39/43] Revert "Always parse on worker pool."

This reverts commit 759a0e5f15e51c7b853aed3ec09f33edd3ac9360.
---
 .../org/rascalmpl/vscode/lsp/TextDocumentState.java  | 12 ++++--------
 .../parametric/ParametricTextDocumentService.java    |  2 +-
 .../vscode/lsp/rascal/RascalTextDocumentService.java |  2 +-
 3 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
index 7a27ef5c7..f41c1fadc 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
@@ -30,7 +30,6 @@
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
-import java.util.concurrent.ExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.BiFunction;
@@ -63,7 +62,6 @@ public class TextDocumentState {
 
     private final BiFunction<ISourceLocation, String, CompletableFuture<ITree>> parser;
     private final ISourceLocation location;
-    private final ExecutorService exec;
 
     private final AtomicReference<Versioned<Update>> current;
     private final AtomicReference<@Nullable Versioned<ITree>> lastWithoutErrors;
@@ -72,12 +70,10 @@ public class TextDocumentState {
     public TextDocumentState(
             BiFunction<ISourceLocation, String, CompletableFuture<ITree>> parser,
             ISourceLocation location,
-            int initialVersion, String initialContent, long initialTimestamp,
-            ExecutorService exec) {
+            int initialVersion, String initialContent, long initialTimestamp) {
 
         this.parser = parser;
         this.location = location;
-        this.exec = exec;
 
         var u = new Update(initialVersion, initialContent, initialTimestamp);
         this.current = new AtomicReference<>(new Versioned<>(initialVersion, u));
@@ -205,7 +201,7 @@ private void parse() {
             logger.debug("Triggering parse for {}", location);
             try {
                 parser.apply(location, content)
-                    .whenCompleteAsync((ITree t, Throwable e) -> {
+                    .whenComplete((ITree t, Throwable e) -> {
                         if (e instanceof CompletionException && e.getCause() != null) {
                             e = e.getCause();
                         }
@@ -230,7 +226,7 @@ private void parse() {
                         // Complete future to get diagnostics
                         var diagnostics = new Versioned<>(version, diagnosticsList);
                         diagnosticsAsync.complete(diagnostics);
-                    }, exec);
+                    });
             } catch (NoContributionException e) {
                 logger.debug("Ignoring missing parser for {}", location, e);
                 treeAsync.completeOnTimeout(new Versioned<>(version, IRascalValueFactory.getInstance().character(0), timestamp), 60, TimeUnit.SECONDS);
@@ -264,6 +260,6 @@ public long getLastModified() {
 
     public TextDocumentState changeParser(BiFunction<ISourceLocation, String, CompletableFuture<ITree>> parsing) {
         var c = getCurrentContent();
-        return new TextDocumentState(parsing, this.location, c.version(), c.get(), getLastModified(), exec);
+        return new TextDocumentState(parsing, this.location, c.version(), c.get(), getLastModified());
     }
 }
diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
index a341f6e9f..ee6b3073f 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/parametric/ParametricTextDocumentService.java
@@ -719,7 +719,7 @@ private ParametricFileFacts facts(ISourceLocation doc) {
 
     private TextDocumentState open(TextDocumentItem doc, long timestamp) {
         return files.computeIfAbsent(Locations.toLoc(doc),
-            l -> new TextDocumentState(contributions(l)::parsing, l, doc.getVersion(), doc.getText(), timestamp, exec));
+            l -> new TextDocumentState(contributions(l)::parsing, l, doc.getVersion(), doc.getText(), timestamp));
     }
 
     private TextDocumentState getFile(ISourceLocation loc) {
diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/rascal/RascalTextDocumentService.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/rascal/RascalTextDocumentService.java
index a13d62b58..e581a3273 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/rascal/RascalTextDocumentService.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/rascal/RascalTextDocumentService.java
@@ -557,7 +557,7 @@ private static <T> T last(List<T> l) {
 
     private TextDocumentState open(TextDocumentItem doc, long timestamp) {
         return documents.computeIfAbsent(Locations.toLoc(doc),
-            l -> new TextDocumentState(availableRascalServices()::parseSourceFile, l, doc.getVersion(), doc.getText(), timestamp, exec));
+            l -> new TextDocumentState(availableRascalServices()::parseSourceFile, l, doc.getVersion(), doc.getText(), timestamp));
     }
 
     private TextDocumentState getFile(TextDocumentIdentifier doc) {

From 1b437ee0018b1fd2204518154b4e90ba6a0d318b Mon Sep 17 00:00:00 2001
From: Sung-Shik Jongmans <sung-shik.jongmans@swat.engineering>
Date: Wed, 15 Apr 2026 07:48:04 +0200
Subject: [PATCH 40/43] Add more log statements to while loop

---
 .../main/java/org/rascalmpl/vscode/lsp/util/Versioned.java    | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
index 7b3c2f430..16c1c6d6b 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
@@ -72,8 +72,12 @@ public static <T> AtomicReference<Versioned<T>> atomic(int version, T object) {
 
     public static <T> boolean replaceIfNewer(AtomicReference<@PolyNull Versioned<T>> current, Versioned<T> maybeNewer) {
         logger.debug("Versioned.replaceIfNewer({}, {})", current, maybeNewer);
+        logger.debug("maybeNewer.version: {}", maybeNewer.version());
+        int i = 1;
         while (true) {
+            logger.debug("Iteration {}: Getting `old`...", i++);
             var old = current.get();
+            logger.debug("Iteration {}: `old` = `{}`", i++, old);
             if (old == null) {
                 logger.debug("old == null");
                 if (current.compareAndSet(old, maybeNewer)) {

From a8a2f8aee99682e26d2afc9b0fccf22cc095d21e Mon Sep 17 00:00:00 2001
From: Sung-Shik Jongmans <sung-shik.jongmans@swat.engineering>
Date: Wed, 15 Apr 2026 08:09:26 +0200
Subject: [PATCH 41/43] Add more log statements to while loop

---
 .../java/org/rascalmpl/vscode/lsp/util/Versioned.java | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
index 16c1c6d6b..7b084f3dd 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
@@ -72,11 +72,18 @@ public static <T> AtomicReference<Versioned<T>> atomic(int version, T object) {
 
     public static <T> boolean replaceIfNewer(AtomicReference<@PolyNull Versioned<T>> current, Versioned<T> maybeNewer) {
         logger.debug("Versioned.replaceIfNewer({}, {})", current, maybeNewer);
-        logger.debug("maybeNewer.version: {}", maybeNewer.version());
+        logger.debug("current==null: {}; maybeNewer.version: {}", current == null, maybeNewer.version());
         int i = 1;
         while (true) {
+            Versioned<T> old = null;
             logger.debug("Iteration {}: Getting `old`...", i++);
-            var old = current.get();
+            try {
+                old = current.get();
+            } catch (Throwable t) {
+                logger.error("{}: {}", t.getClass(), t.getMessage());
+                t.printStackTrace();
+                throw t;
+            }
             logger.debug("Iteration {}: `old` = `{}`", i++, old);
             if (old == null) {
                 logger.debug("old == null");

From a4984855a17d859cb9cee97dd88e41877cbc14d1 Mon Sep 17 00:00:00 2001
From: Sung-Shik Jongmans <sung-shik.jongmans@swat.engineering>
Date: Wed, 15 Apr 2026 08:25:43 +0200
Subject: [PATCH 42/43] Add more log statements to while loop

---
 .../src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
index 7b084f3dd..360df3e0e 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/util/Versioned.java
@@ -81,7 +81,7 @@ public static <T> boolean replaceIfNewer(AtomicReference<@PolyNull Versioned<T>>
                 old = current.get();
             } catch (Throwable t) {
                 logger.error("{}: {}", t.getClass(), t.getMessage());
-                t.printStackTrace();
+                // t.printStackTrace();
                 throw t;
             }
             logger.debug("Iteration {}: `old` = `{}`", i++, old);

From df5a6d1f7e70de00f14f2bda8eefdccd0ffc10ce Mon Sep 17 00:00:00 2001
From: Sung-Shik Jongmans <sung-shik.jongmans@swat.engineering>
Date: Wed, 15 Apr 2026 08:49:45 +0200
Subject: [PATCH 43/43] Fix issue that an outer class instance
 (`TextDocumentState`) wasn't properly initialized yet when an inner class
 instance (`Update`) was created. The inner class instance would use an
 uninitialized field of the outer class instance, resulting in an NPE.

---
 .../main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
index f41c1fadc..e9bda27c8 100644
--- a/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
+++ b/rascal-lsp/src/main/java/org/rascalmpl/vscode/lsp/TextDocumentState.java
@@ -74,11 +74,11 @@ public TextDocumentState(
 
         this.parser = parser;
         this.location = location;
+        this.lastWithoutErrors = new AtomicReference<>();
+        this.last = new AtomicReference<>();
 
         var u = new Update(initialVersion, initialContent, initialTimestamp);
         this.current = new AtomicReference<>(new Versioned<>(initialVersion, u));
-        this.lastWithoutErrors = new AtomicReference<>();
-        this.last = new AtomicReference<>();
     }
 
     public ISourceLocation getLocation() {