Add NXF_DEV launcher support for automated dev builds

.github/workflows/dev-build-comment.yml

@@ -0,0 +1,101 @@
+name: Dev build comment
+
+# Posts a comment on each pull request with instructions for testing the
+# automated dev build of that PR, published by the nextflow-dev-builds repo.
+# The comment is created once and then updated in place on each push.
+#
+# Uses pull_request_target so the comment can also be posted on PRs from
+# forks. This is safe because the workflow never checks out or executes any
+# code from the PR: it only reads PR metadata and the VERSION file, whose
+# content is validated before use.
+
+on:
+  pull_request_target:
+    types: [opened, reopened, synchronize]
+
+permissions: {}
+
+concurrency:
+  group: dev-build-comment-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  comment:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      # Trigger an immediate build instead of waiting for the scheduled run in
+      # the dev-builds repo. Requires the DEV_BUILDS_DISPATCH_TOKEN secret
+      # (fine-grained PAT with actions:write on nextflow-dev-builds). Failure
+      # is reported in the PR comment but never blocks anything.
+      - name: Trigger dev build
+        id: dispatch
+        env:
+          GH_TOKEN: ${{ secrets.DEV_BUILDS_DISPATCH_TOKEN }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          DEV_REPO: nextflow-io/nextflow-dev-builds
+        run: |
+          set -euo pipefail
+          if [ -z "$GH_TOKEN" ]; then
+            echo "::notice::DEV_BUILDS_DISPATCH_TOKEN is not set, the scheduled build will pick up this push instead"
+            echo "status=scheduled" >> "$GITHUB_OUTPUT"
+          elif gh workflow run build.yml -R "$DEV_REPO" -f pr="$PR_NUMBER"; then
+            echo "status=triggered" >> "$GITHUB_OUTPUT"
+          else
+            echo "::warning::Failed to trigger dev build in $DEV_REPO, the scheduled build will pick up this push instead"
+            echo "status=failed" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Create or update comment
+        env:
+          GH_TOKEN: ${{ github.token }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+          DEV_REPO: nextflow-io/nextflow-dev-builds
+          MARKER: '<!-- dev-build-comment -->'
+          DISPATCH_STATUS: ${{ steps.dispatch.outputs.status }}
+        run: |
+          set -euo pipefail
+          base=$(gh api "repos/$GITHUB_REPOSITORY/contents/VERSION?ref=$HEAD_SHA" --jq .content | base64 -d | tr -d '[:space:]')
+          version="${base}-pr-${PR_NUMBER}-${HEAD_SHA:0:7}"
+
+          case "$DISPATCH_STATUS" in
+            triggered) timing="shortly (build triggered automatically)" ;;
+            failed)    timing="within about 30 minutes (automatic build trigger failed, falling back to the scheduled build)" ;;
+            *)         timing="within about 30 minutes (next scheduled build)" ;;
+          esac
+          # the VERSION file in a PR is attacker-controlled, so only allow safe characters
+          if [[ ! "$version" =~ ^[A-Za-z0-9.\-]+$ ]]; then
+            echo "unsafe version string '$version', skipping comment"
+            exit 0
+          fi
+          body=$(cat <<EOF
+          $MARKER
+          ## 📦 Nextflow dev build
+
+          A development build of this PR (commit \`${HEAD_SHA:0:7}\`) will be [published](https://github.com/$DEV_REPO/releases/tag/v${version}) ${timing}. Test it with:
+
+          \`\`\`bash
+          NXF_DEV=pr-${PR_NUMBER} nextflow run <pipeline>
+          \`\`\`
+
+          Or, with Nextflow versions that don't support \`NXF_DEV\` yet:
+
+          \`\`\`bash
+          NXF_BASE=https://github.com/$DEV_REPO/releases/download \\
+          NXF_VER=${version} \\
+          nextflow run <pipeline>
+          \`\`\`
+
+          For testing purposes only. See [$DEV_REPO](https://github.com/$DEV_REPO) for details. This comment is updated on each push.
+          EOF
+          )
+
+          comment_id=$(gh api "repos/$GITHUB_REPOSITORY/issues/$PR_NUMBER/comments?per_page=100" --paginate \
+            --jq '[.[] | select(.body | startswith(env.MARKER)) | .id] | first // empty' | head -n1)
+          if [ -n "$comment_id" ]; then
+            gh api --silent -X PATCH "repos/$GITHUB_REPOSITORY/issues/comments/$comment_id" -f body="$body"
+          else
+            gh api --silent -X POST "repos/$GITHUB_REPOSITORY/issues/$PR_NUMBER/comments" -f body="$body"
+          fi

.github/workflows/dev-build-dispatch.yml

@@ -0,0 +1,34 @@
+name: Dev build dispatch
+
+# Triggers an immediate dev build of master in nextflow-io/nextflow-dev-builds
+# on each push, instead of waiting for the scheduled build there.
+#
+# Requires the DEV_BUILDS_DISPATCH_TOKEN secret (fine-grained PAT with
+# actions:write on the nextflow-dev-builds repo). Without it, the push is
+# picked up by the scheduled build within about 30 minutes.
+
+on:
+  push:
+    branches: [master]
+
+permissions: {}
+
+jobs:
+  dispatch:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Trigger dev build of master
+        env:
+          GH_TOKEN: ${{ secrets.DEV_BUILDS_DISPATCH_TOKEN }}
+          DEV_REPO: nextflow-io/nextflow-dev-builds
+        run: |
+          set -euo pipefail
+          if [ -z "$GH_TOKEN" ]; then
+            echo "::notice::DEV_BUILDS_DISPATCH_TOKEN is not set, the scheduled build in $DEV_REPO will pick up this push within about 30 minutes"
+            exit 0
+          fi
+          if gh workflow run build.yml -R "$DEV_REPO" -f branch=master; then
+            echo "dev build of master triggered in $DEV_REPO"
+          else
+            echo "::warning::Failed to trigger dev build in $DEV_REPO, the scheduled build will pick up this push within about 30 minutes"
+          fi

docs/reference/env-vars.md

@@ -69,6 +69,11 @@ The following environment variables control the configuration of the Nextflow ru
   :::
 : Defines the DSL version that should be used in not specified otherwise in the script of config file (default: `2`)
 
+`NXF_DEV`
+: :::{versionadded} 26.05.0-edge
+  :::
+: Use an automated development build of Nextflow, for testing purposes only. Set to `master` for the latest build of the master branch, or `pr-<number>` for the latest build of a pull request. Builds are published in the [nextflow-dev-builds](https://github.com/nextflow-io/nextflow-dev-builds) repository.
+
 `NXF_DISABLE_CHECK_LATEST`
 : :::{versionadded} 23.09.0-edge
   :::

nextflow

@@ -16,6 +16,26 @@
 #
 
 [[ "$NXF_DEBUG" == 'x' ]] && set -x
+
+# NXF_DEV selects an automated development build, for testing purposes only:
+# `NXF_DEV=master` for the latest build of the master branch, `NXF_DEV=pr-1234`
+# for the latest build of a pull request. See the repository below for details.
+if [[ $NXF_DEV ]]; then
+    NXF_DEV_REPO=${NXF_DEV_REPO:-'https://github.com/nextflow-io/nextflow-dev-builds'}
+    NXF_BASE=${NXF_BASE:-$NXF_DEV_REPO/releases/download}
+    if [[ ! $NXF_VER ]]; then
+        if command -v curl &>/dev/null; then
+            NXF_VER=$(curl -fsSL "$NXF_DEV_REPO/raw/master/latest/$NXF_DEV" 2>/dev/null)
+        elif command -v wget &>/dev/null; then
+            NXF_VER=$(wget -qO- "$NXF_DEV_REPO/raw/master/latest/$NXF_DEV" 2>/dev/null)
+        fi
+        if [[ ! $NXF_VER ]]; then
+            >&2 echo "ERROR: Cannot find a Nextflow dev build for '$NXF_DEV' -- check $NXF_DEV_REPO"
+            exit 1
+        fi
+    fi
+fi
+
 NXF_VER=${NXF_VER:-'26.04.3'}
 NXF_ORG=${NXF_ORG:-'nextflow-io'}
 NXF_HOME=${NXF_HOME:-$HOME/.nextflow}
@@ -264,6 +284,7 @@ while [[ $# != 0 ]]; do
       ;;
     -self-update|self-update)
       if [[ ! "$cmd" ]]; then
+      [[ $NXF_DEV ]] && die "Cannot self-update when NXF_DEV is set -- unset it and try again"
       [[ -z $NXF_EDGE && $NXF_VER = *-edge ]] && NXF_EDGE=1
       unset NXF_VER
       install "$0" update