From d645d69c6b0e69f24e1efb6ef453d1bf48bd8cec Mon Sep 17 00:00:00 2001
From: Marco Walz <marco.walz@dfinity.org>
Date: Mon, 3 Aug 2026 16:51:46 +0200
Subject: [PATCH] fix(generate-changelog): do not fail on release commits or
 empty changelogs

The generate_changelog workflow fires on every push to main, including when a
release PR is merged. Commitizen then has nothing to add to the changelog and
exits non-zero, failing the job. Two variants have been observed in
dfinity/icp-js-core:

- exit 3 ("No commits found") when the tag already exists
- exit 16 ("No tag found to do an incremental changelog") when the tag has not
  been pushed yet, which is the common case since the release tag is pushed
  manually a couple of minutes after the release PR merges

Both are no-ops in intent, not errors. Two complementary changes:

- Skip the changelog steps entirely when the head commit subject looks like a
  release commit, via a new release_commit_pattern input. This covers the exit
  16 case, whose cause is the tag not existing yet.
- Treat commitizen exit 3 as success in actions/generate-changelog, so a
  release commit that slips past the subject check (retitled release PR, or a
  repo that permits merge commits) still does not fail the job.

Exit 16 deliberately remains fatal. Unlike exit 3 it is ambiguous: it also
fires when tags are genuinely unavailable, for example a shallow clone or a
regression in tag fetching. Swallowing it would turn a loud failure into a
silent no-op where the changelog quietly stops being generated.

Closes #75

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
---
 .github/workflows/generate-changelog.yaml | 28 +++++++++++++++++++++++
 actions/generate-changelog/action.yaml    | 15 +++++++++++-
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/generate-changelog.yaml b/.github/workflows/generate-changelog.yaml
index 75caf29..61497b6 100644
--- a/.github/workflows/generate-changelog.yaml
+++ b/.github/workflows/generate-changelog.yaml
@@ -48,6 +48,12 @@ on:
         default: 'chore: generate changelog'
         type: string
 
+      release_commit_pattern:
+        description: 'Skip changelog generation when the head commit subject matches this extended regular expression. Set to an empty string to disable the check.'
+        required: false
+        default: '^chore:[[:space:]]release([[:space:]]|$)'
+        type: string
+
       token_app_id:
         description: 'A GitHub App ID used to generate an access token to create a pull request.'
         required: true
@@ -94,18 +100,40 @@ jobs:
           fetch-depth: 0
           fetch-tags: true
 
+      - name: Check for release commit
+        id: release_commit
+        shell: bash
+        env:
+          RELEASE_COMMIT_PATTERN: ${{ inputs.release_commit_pattern }}
+        run: |
+          subject=$(git log -1 --format=%s)
+
+          # A release commit bumps the project version, and the matching tag is usually not
+          # pushed yet when this workflow runs. Commitizen then has nothing to changelog and
+          # exits non-zero, failing the job. Skip those commits entirely.
+          if [ -n "$RELEASE_COMMIT_PATTERN" ] && [[ "$subject" =~ $RELEASE_COMMIT_PATTERN ]]; then
+            echo 'skip=true' >> "$GITHUB_OUTPUT"
+            echo "::notice::Head commit is a release commit ('$subject'); skipping changelog generation."
+          else
+            echo 'skip=false' >> "$GITHUB_OUTPUT"
+          fi
+
       - name: Setup Python
+        if: steps.release_commit.outputs.skip != 'true'
         uses: dfinity/ci-tools/actions/setup-python@afeee4fbdc0683a88ec5a74ed7f59a2ce0e833ad # main
 
       - name: Setup Commitizen
+        if: steps.release_commit.outputs.skip != 'true'
         uses: dfinity/ci-tools/actions/setup-commitizen@afeee4fbdc0683a88ec5a74ed7f59a2ce0e833ad # main
 
       - name: Generate changelog
+        if: steps.release_commit.outputs.skip != 'true'
         uses: dfinity/ci-tools/actions/generate-changelog@afeee4fbdc0683a88ec5a74ed7f59a2ce0e833ad # main
         with:
           file_name: ${{ inputs.file_name }}
 
       - name: Create pull request
+        if: steps.release_commit.outputs.skip != 'true'
         uses: dfinity/ci-tools/actions/create-pr@afeee4fbdc0683a88ec5a74ed7f59a2ce0e833ad # main
         with:
           branch_name: ${{ inputs.branch_name }}
diff --git a/actions/generate-changelog/action.yaml b/actions/generate-changelog/action.yaml
index d34be07..233a6a6 100644
--- a/actions/generate-changelog/action.yaml
+++ b/actions/generate-changelog/action.yaml
@@ -14,4 +14,17 @@ runs:
       shell: bash
       env:
         FILE_NAME: ${{ inputs.file_name }}
-      run: cz changelog --incremental --merge-prerelease --file-name="$FILE_NAME" --version-scheme semver2
+      run: |
+        set +e
+        cz changelog --incremental --merge-prerelease --file-name="$FILE_NAME" --version-scheme semver2
+        exit_code=$?
+        set -e
+
+        # Commitizen exits 3 when it finds no commits to add to the changelog. That is a
+        # no-op rather than a failure, so it must not fail the job.
+        if [ "$exit_code" -eq 3 ]; then
+          echo "::notice::No commits to add to the changelog; nothing to do."
+          exit 0
+        fi
+
+        exit "$exit_code"