Fix Copilot CLI toolcache hit not creating /usr/local/bin/copilot by Copilot · Pull Request #53490 · github/gh-aw

Copilot · 2026-08-17T21:00:45Z

On a runner toolcache hit, install_copilot_cli.sh activated the cached CLI by appending its directory to GITHUB_PATH and returned early, never creating ${INSTALL_DIR}/copilot. The agent is spawned with the literal absolute path /usr/local/bin/copilot, so spawn() failed with ENOENT and the run died before producing output ("Engine Failure: the copilot engine terminated before producing output"). Because it depends on what the runner happens to have cached, the same unchanged workflow succeeded or failed non-deterministically.

Changes

actions/setup/sh/install_copilot_cli.sh
- activate_cached_copilot_bin now exports the cached dir to GITHUB_PATH and falls through to install the exec wrapper at ${INSTALL_DIR}/copilot, so the canonical path exists regardless of how the CLI was provisioned. The wrapper-install branch was previously dead code under Actions, where GITHUB_PATH is always set.
- Skips wrapper creation when the cached binary already is ${INSTALL_DIR}/copilot, avoiding a self-exec loop.
- Cached-install verification now fails fast if ${INSTALL_DIR}/copilot is missing or non-executable, so the failure surfaces in the setup step rather than as an opaque agent crash.
- Added COPILOT_INSTALL_DIR override (consistent with the existing COPILOT_COMPAT_URL / COPILOT_COMPAT_BUNDLED_PATH test hooks) so tests can exercise the real install path without writing to /usr/local/bin.

  if [ -n "${GITHUB_PATH:-}" ]; then
    echo "$cached_copilot_dir" >> "${GITHUB_PATH}"
  fi
  # ...falls through: wrapper is installed at ${INSTALL_DIR}/copilot

pkg/cli/install_copilot_cli_test.go — toolcache tests now assert the canonical path is materialized:
- explicit-version hit: wrapper exists, references the cached binary, and executes (--version);
- dev-mode compat resolution (GH_AW_COMPILED_VERSION=dev): wrapper points at the best cached candidate;
- rootless test updated for the new log messages.
Changeset added.

The alternatives noted in the issue — emitting the resolved path into the lock file, or a PATH fallback in copilot_harness.cjs — are larger and left out; the wrapper matches the script's own stated preference.

Fixes Copilot CLI toolcache cache-hit never creates /usr/local/bin/copilot → agent dies with spawn ENOENT ("engine terminated before producing output") #53481

Run: https://github.com/github/gh-aw/actions/runs/32075123011> Generated by 👨‍🍳 PR Sous Chef · gpt54 · 7.25 AIC · ⌖ 7.79 AIC · ⊞ 8.8K · ◷

_{Comment /souschef to run again}

Run: https://github.com/github/gh-aw/actions/runs/32082636829> Generated by 👨‍🍳 PR Sous Chef · gpt54 · 14.1 AIC · ⌖ 7.81 AIC · ⊞ 8.8K · ◷

_{Comment /souschef to run again}

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot

Pull request overview

Fixes cached Copilot CLI activation by ensuring the canonical executable path exists.

Changes:

Installs a wrapper for toolcache hits and verifies the canonical path.
Adds a test-only install-directory override.
Expands regression tests and adds a patch changeset.

Show a summary per file

File	Description
`actions/setup/sh/install_copilot_cli.sh`	Materializes the canonical Copilot wrapper.
`pkg/cli/install_copilot_cli_test.go`	Tests wrapper creation and execution.
`.changeset/patch-fix-copilot-toolcache-wrapper.md`	Documents the patch.

Review details

💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.

Files reviewed: 3/3 changed files
Comments generated: 1
Review effort level: Balanced

Copilot · 2026-08-18T00:13:13Z

+  if [ "$cached_copilot_bin" = "${INSTALL_DIR}/copilot" ]; then
+    echo "  Cached binary already lives at ${INSTALL_DIR}/copilot — no wrapper needed"
    return 0


Addressed in 5f5d213. The new test sets COPILOT_INSTALL_DIR to the selected toolcache bin, verifies the cached file is not replaced by a wrapper, and executes it successfully.

gh-aw-bot · 2026-08-17T22:21:14Z

@copilot PR sous-chef triage: branch refresh was requested. Please run the pr-finisher skill and report any remaining blockers on this PR.

Run: https://github.com/github/gh-aw/actions/runs/32075123011

Generated by 👨‍🍳 PR Sous Chef · gpt54 · 7.25 AIC · ⌖ 7.79 AIC · ⊞ 8.8K · ◷
_{Comment /souschef to run again}

Co-authored-by: gh-aw-bot <259018956+gh-aw-bot@users.noreply.github.com>

Copilot · 2026-08-17T22:53:55Z

@copilot PR sous-chef triage: branch refresh was requested. Please run the pr-finisher skill and report any remaining blockers on this PR.

Run: https://github.com/github/gh-aw/actions/runs/320751...

Ran pr-finisher and completed the branch refresh cleanup in 19dce2b. Local formatting, lint, focused installer tests, full tests, recompilation, and the final impacted-test gate pass. Remaining blockers: the existing unresolved Copilot review thread, maintainer review, and approval/re-trigger of CI checks currently marked action_required (those runs created zero jobs).

pelikhan · 2026-08-17T23:02:57Z

@lpcox review

gh-aw-bot · 2026-08-18T00:04:41Z

@copilot Please review any remaining unresolved feedback on this PR, refresh the branch if needed, then run the pr-finisher skill and report back with the current blockers and validation results.

Run: https://github.com/github/gh-aw/actions/runs/32082636829

Generated by 👨‍🍳 PR Sous Chef · gpt54 · 14.1 AIC · ⌖ 7.81 AIC · ⊞ 8.8K · ◷
_{Comment /souschef to run again}

Co-authored-by: gh-aw-bot <259018956+gh-aw-bot@users.noreply.github.com>

Copilot · 2026-08-18T00:22:52Z

@copilot Please review any remaining unresolved feedback on this PR, refresh the branch if needed, then run the pr-finisher skill and report back with the current blockers and validation results.

...

Ran pr-finisher. Commit 00005cb adds the requested self-wrapper regression test; I replied to the Copilot thread, but it still requires UI resolution. The branch is current with main. Formatting, lint, focused installer tests, impacted unit tests, recompilation, secret scan, and CodeQL pass. Full make test is blocked by a refreshed-base regression in TestCopilotEngineInstallationWithCopilotSDKDriver (current main removed ripgrep installation but the test still expects 3 steps). Current CGO/CWI checks are approval-gated (action_required) with zero jobs, so maintainer CI approval/re-trigger and review remain.

github-actions · 2026-08-18T00:31:18Z

PR Triage

Category: bug · Risk: medium · Score: 73/100

Breakdown: impact 35/50 · urgency 20/30 · quality 18/20

Recommended action: fast_track

Fixes a real breakage: when the Copilot CLI toolcache is hit, /usr/local/bin/copilot was not being (re)created, breaking install_copilot_cli.sh on cache-hit runs. Includes a changeset and a new unit test (+93/-5, 3 files). This is the highest-priority PR in this run — affects Copilot CLI availability wherever the tool cache is reused. Recommend expedited human review.

Generated by 🔧 PR Triage Agent · auto · 46.6 AIC · ⌖ 1.9 AIC · ⊞ 8.3K · ◷

Initial plan

ecd3a99

Copilot AI assigned Copilot and pelikhan Aug 17, 2026

Copilot started work on behalf of pelikhan August 17, 2026 21:00 View session

Copilot AI linked an issue Aug 17, 2026 that may be closed by this pull request

Copilot CLI toolcache cache-hit never creates /usr/local/bin/copilot → agent dies with spawn ENOENT ("engine terminated before producing output") #53481

Open

Always install /usr/local/bin/copilot wrapper on toolcache hit

d56242f

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix Copilot CLI toolcache cache-hit issue causing engine termination~~ Fix Copilot CLI toolcache hit not creating /usr/local/bin/copilot Aug 17, 2026

Copilot AI requested a review from pelikhan August 17, 2026 21:11

Copilot finished work on behalf of pelikhan August 17, 2026 21:11

pelikhan marked this pull request as ready for review August 17, 2026 21:36

Copilot AI balanced review requested due to automatic review settings August 17, 2026 21:36

Copilot started reviewing on behalf of pelikhan August 17, 2026 21:37 View session

Copilot AI reviewed Aug 17, 2026

View reviewed changes

github-actions Bot mentioned this pull request Aug 17, 2026

[pr-sous-chef] PR Sous Chef run report #53451

Closed

Merge branch 'main' into copilot/fix-copilot-cli-toolcache-issue-again

23e36e7

Copilot started work on behalf of gh-aw-bot August 17, 2026 22:21 View session

Copilot AI and others added 2 commits August 17, 2026 22:25

Start PR readiness review

7a29c88

Co-authored-by: gh-aw-bot <259018956+gh-aw-bot@users.noreply.github.com>

Remove unrelated workflow delta after refresh

19dce2b

Co-authored-by: gh-aw-bot <259018956+gh-aw-bot@users.noreply.github.com>

Copilot finished work on behalf of gh-aw-bot August 17, 2026 22:54

Copilot AI requested a review from gh-aw-bot August 17, 2026 22:54

Merge branch 'main' into copilot/fix-copilot-cli-toolcache-issue-again

d3327a9

github-actions Bot mentioned this pull request Aug 18, 2026

[pr-sous-chef] PR Sous Chef run report #53530

Open

Copilot started work on behalf of gh-aw-bot August 18, 2026 00:05 View session

Test cached Copilot binary self-wrapper guard

00005cb

Co-authored-by: gh-aw-bot <259018956+gh-aw-bot@users.noreply.github.com>

Copilot finished work on behalf of gh-aw-bot August 18, 2026 00:23

github-actions Bot added pr-action:fast_track pr-agent:copilot pr-priority:high pr-risk:medium pr-type:bug labels Aug 18, 2026

github-actions Bot mentioned this pull request Aug 18, 2026

[PR Triage Report] PR Triage Report — Run 32084259320 (7 PRs) #53534

Open

Navigation Menu

Uh oh!

Fix Copilot CLI toolcache hit not creating /usr/local/bin/copilot - #53490

Fix Copilot CLI toolcache hit not creating /usr/local/bin/copilot#53490
pelikhan with Copilot wants to merge 7 commits into
mainfrom
copilot/fix-copilot-cli-toolcache-issue-again

Copilot AI commented Aug 17, 2026 •

edited by github-actions Bot

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Aug 18, 2026

Uh oh!

gh-aw-bot commented Aug 17, 2026

Uh oh!

Copilot AI commented Aug 17, 2026

Uh oh!

pelikhan commented Aug 17, 2026

Uh oh!

gh-aw-bot commented Aug 18, 2026

Uh oh!

Copilot AI commented Aug 18, 2026

Uh oh!

github-actions Bot commented Aug 18, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Uh oh!

Conversation

Copilot AI commented Aug 17, 2026 • edited by github-actions Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Changes

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Review details

Uh oh!

Copilot AI Aug 18, 2026

Choose a reason for hiding this comment

Uh oh!

gh-aw-bot commented Aug 17, 2026

Uh oh!

Copilot AI commented Aug 17, 2026

Uh oh!

pelikhan commented Aug 17, 2026

Uh oh!

gh-aw-bot commented Aug 18, 2026

Uh oh!

Copilot AI commented Aug 18, 2026

Uh oh!

github-actions Bot commented Aug 18, 2026

PR Triage

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Copilot AI commented Aug 17, 2026 •

edited by github-actions Bot

Loading