Rebase onto main: align with wasm-shim-merge architecture, pin CI toolchain

This branch predates the 2026-04-20 wasm-shim-merge work and the bd-at72
toolchain pin; rebasing onto current main needed alignment beyond
conflict resolution:

- wasm-c-shim: the rebase carried main's evolved c_shim.rs content into
  shim.rs via rename detection; declare the wasm-printf-fmt dependency
  it uses for snprintf/vsnprintf.
- Root Cargo.toml: patch tree-sitter-language to the local wasm-shim
  fork (same patch wasm-quarto-hub-client uses) so tree-sitter core does
  not compile upstream's wasm32 stdio/stdlib/string stubs, which collide
  with wasm-c-shim at link time. The fork has byte-identical Rust source
  and a no-op build.rs on native targets.
- wasm-tests CI: run on the pinned toolchain from rust-toolchain.toml
  (now a nightly with rust-src and the wasm32 target) instead of
  RUSTUP_TOOLCHAIN=nightly — bd-at72 pinned the toolchain because later
  nightlies SIGSEGV in LLVM ThinLTO on wasm32 builds of this workspace.
  The E0152 duplicate-lang-item conflict the override worked around no
  longer reproduces on the pinned toolchain.
- wasm_lua.rs: SourceInfo::for_test() (SourceInfo::default() is
  deprecated under -D deprecated), and pass the new attribution
  argument (None) to apply_lua_filters.
- Regenerate Cargo.lock and crates/wasm-quarto-hub-client/Cargo.lock.

Verified: cargo build + nextest workspace green (9862 passed); all 6
wasm tests pass under wasm-bindgen-test-runner (macOS, Homebrew LLVM
clang, pinned nightly); production build-wasm.js succeeds.

Author: gordonwoodhull

.github/workflows/test-suite.yml

@@ -183,21 +183,18 @@ jobs:
   wasm-tests:
     name: WASM Tests
     runs-on: ubuntu-latest
-    # Override rust-toolchain.toml so the rustup proxy doesn't auto-install the
-    # prebuilt wasm32-unknown-unknown target. We need -Zbuild-std to rebuild
-    # core from source, and the prebuilt sysroot causes E0152 (duplicate lang
-    # item). The production WASM build avoids this because wasm-quarto-hub-client
-    # is excluded from the workspace and gets an isolated target/ directory.
-    env:
-      RUSTUP_TOOLCHAIN: nightly
+    # Uses the pinned toolchain from rust-toolchain.toml, which is already a
+    # nightly with rust-src (required by -Zbuild-std) and the wasm32 target.
+    # Do NOT override with latest nightly: bd-at72 pinned the toolchain because
+    # newer nightlies SIGSEGV in LLVM ThinLTO when building this workspace for
+    # wasm32-unknown-unknown. (The E0152 duplicate-lang-item conflict between
+    # the prebuilt wasm32 sysroot and -Zbuild-std that this job originally
+    # worked around no longer reproduces on the pinned toolchain.)
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 1
 
-      - name: Install Rust nightly with rust-src
-        run: rustup toolchain install nightly --component rust-src --profile minimal
-
       - name: Set up Clang
         uses: egor-tensin/setup-clang@v1
         with:

Cargo.lock

@@ -274,6 +274,13 @@ verbose_file_reads = "warn"
 
 [patch.crates-io]
 lua-src = { path = "crates/lua-src-wasm" }
+# Neutralize tree-sitter-language's upstream wasm32 stdio/stdlib/string C
+# stubs so wasm-c-shim is the single source of truth for C stdlib symbols
+# in workspace wasm32 builds (the pampa wasm_lua tests). Same patch as
+# wasm-quarto-hub-client's; identical Rust source on native targets, and
+# its build.rs is a no-op off-wasm32. See
+# claude-notes/plans/2026-04-20-wasm-shim-merge.md.
+tree-sitter-language = { path = "crates/tree-sitter-language-wasm-shim" }
 # Fork of runtimelib that adds venv-aware kernelspec discovery
 # (`data_dirs_with_jupyter_paths`, `find_kernelspec_with_jupyter_paths`)
 # and threads `searched_paths` through `RuntimeError::KernelNotFound`.

Cargo.toml

@@ -87,9 +87,9 @@ end
         blocks: vec![Block::Paragraph(Paragraph {
             content: vec![Inline::Str(Str {
                 text: "hello".to_string(),
-                source_info: quarto_source_map::SourceInfo::default(),
+                source_info: quarto_source_map::SourceInfo::for_test(),
             })],
-            source_info: quarto_source_map::SourceInfo::default(),
+            source_info: quarto_source_map::SourceInfo::for_test(),
         })],
     };
     let context = ASTContext::new();
@@ -100,6 +100,7 @@ end
         &[PathBuf::from("/project/uppercase.lua")],
         "html",
         runtime,
+        None,
     )
     .await
     .expect("filter execution failed");
@@ -198,9 +199,9 @@ end
         blocks: vec![Block::Paragraph(Paragraph {
             content: vec![Inline::Str(Str {
                 text: "test".to_string(),
-                source_info: quarto_source_map::SourceInfo::default(),
+                source_info: quarto_source_map::SourceInfo::for_test(),
             })],
-            source_info: quarto_source_map::SourceInfo::default(),
+            source_info: quarto_source_map::SourceInfo::for_test(),
         })],
     };
 
@@ -210,6 +211,7 @@ end
         &[PathBuf::from("/project/check_io.lua")],
         "html",
         runtime,
+        None,
     )
     .await
     .expect("filter with io checks failed — synthetic io may not be registered");
@@ -257,9 +259,9 @@ end
         blocks: vec![Block::Paragraph(Paragraph {
             content: vec![Inline::Str(Str {
                 text: "test".to_string(),
-                source_info: quarto_source_map::SourceInfo::default(),
+                source_info: quarto_source_map::SourceInfo::for_test(),
             })],
-            source_info: quarto_source_map::SourceInfo::default(),
+            source_info: quarto_source_map::SourceInfo::for_test(),
         })],
     };
 
@@ -269,6 +271,7 @@ end
         &[PathBuf::from("/project/check_os.lua")],
         "html",
         runtime,
+        None,
     )
     .await
     .expect("filter with os checks failed — synthetic os may not be registered");

crates/pampa/tests/wasm_lua.rs

@@ -9,5 +9,10 @@ edition = "2021"
 license.workspace = true
 description = "C stdlib shims for wasm32-unknown-unknown (no libc)"
 
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+# snprintf/vsnprintf formatting engine used by the shim's printf-family
+# symbols (see the wasm-shim-merge plan, 2026-04-20).
+wasm-printf-fmt = { path = "../wasm-printf-fmt" }
+
 [lints]
 workspace = true

crates/wasm-c-shim/Cargo.toml

@@ -655,12 +655,20 @@ pub unsafe extern "C" fn isxdigit(c: c_int) -> c_int {
 
 #[no_mangle]
 pub unsafe extern "C" fn toupper(c: c_int) -> c_int {
-    if islower(c) != 0 { c - 32 } else { c }
+    if islower(c) != 0 {
+        c - 32
+    } else {
+        c
+    }
 }
 
 #[no_mangle]
 pub unsafe extern "C" fn tolower(c: c_int) -> c_int {
-    if isupper(c) != 0 { c + 32 } else { c }
+    if isupper(c) != 0 {
+        c + 32
+    } else {
+        c
+    }
 }
 
 /* ====================================================================== */
@@ -669,7 +677,11 @@ pub unsafe extern "C" fn tolower(c: c_int) -> c_int {
 
 #[no_mangle]
 pub unsafe extern "C" fn abs(x: c_int) -> c_int {
-    if x < 0 { -x } else { x }
+    if x < 0 {
+        -x
+    } else {
+        x
+    }
 }
 
 #[no_mangle]

crates/wasm-c-shim/src/shim.rs

@@ -150,14 +150,13 @@ instead: `CC_wasm32_unknown_unknown=/opt/homebrew/opt/llvm/bin/clang`.
 - You must use `--test wasm_lua` to select only the WASM test file.
   Running `cargo test -p pampa --target wasm32` without `--test` will fail because
   native tests can't compile for wasm32.
-- The prebuilt `wasm32-unknown-unknown` target (installed by `rust-toolchain.toml`)
-  conflicts with `-Zbuild-std` when building within the workspace — both produce a
-  `core` crate, causing E0152 (duplicate lang item). The production build avoids this
-  because `wasm-quarto-hub-client` is excluded from the workspace. The CI job sets
-  `RUSTUP_TOOLCHAIN=nightly` to bypass `rust-toolchain.toml`, so the prebuilt target
-  is never installed. Locally, you can either set `RUSTUP_TOOLCHAIN=nightly` or
-  remove the target before testing (`rustup target remove wasm32-unknown-unknown`)
-  and re-add it afterward for the production build.
+- The pinned toolchain in `rust-toolchain.toml` (a nightly with `rust-src` and the
+  wasm32 target) is what both CI and local runs should use — no `RUSTUP_TOOLCHAIN`
+  override. Do not substitute a newer nightly: bd-at72 pinned the toolchain because
+  later nightlies SIGSEGV in LLVM ThinLTO when building this workspace for wasm32.
+  (An earlier iteration of this setup hit E0152 duplicate-lang-item conflicts
+  between the prebuilt wasm32 sysroot and `-Zbuild-std`; that no longer reproduces
+  on the pinned toolchain with the prebuilt target installed.)
 - The pampa `[[bin]]` targets (`pampa`, `ast-reconcile`) use `required-features` to
   prevent compilation when running WASM tests. Cargo builds bin targets alongside
   integration tests by default (rust-lang/cargo#12980); the `required-features` gate