[Bug] fatal: ref HEAD is not a symbolic ref thrown by Buildx in CI workflow triggered by a PR

[tschaffter]

Is there an existing issue for this?

• I have searched the existing issues

What product(s) are you seeing the problem on?

Sage Monorepo

Current behavior

This bug is following the merge of this PR: #2538

The task build-image fails when run by the CI workflow in PRs.

 nx run openchallenges-api-docs:build-image


>  Docker info 

/usr/bin/docker version
Client: Docker Engine - Community
 Version:           24.0.5
 API version:       1.43
 Go version:        go1.20.6
 Git commit:        ced0996
 Built:             Fri Jul 21 20:35:18 2023
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          24.0.5
  API version:      1.43 (minimum version 1.12)
  Go version:       go1.20.6
  Git commit:       a61e2b4
  Built:            Fri Jul 21 20:35:18 2023
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.28
  GitCommit:        ae07eda36dd25f8a1b98dfbf587313b99c0190bb
 runc:
  Version:          1.1.12
  GitCommit:        v1.1.12-0-g51d5e94
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0
/usr/bin/docker info
Client: Docker Engine - Community
 Version:    24.0.5
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.12.1
    Path:     /home/vscode/.docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.24.6
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 0
 Server Version: 24.0.5
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: false
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: runc io.containerd.runc.v2
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: ae07eda36dd25f8a1b98dfbf587313b99c0190bb
 runc version: v1.1.12-0-g51d5e94
 init version: de40ad0
 Security Options:
  apparmor
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.5.0-1015-azure
 Operating System: Ubuntu 22.04.2 LTS (containerized)
 OSType: linux
 Architecture: x86_64
 CPUs: 4
 Total Memory: 15.61GiB
 Name: 0848af3701b8
 ID: d9e9d8bc-e782-456c-a4bc-d7e79f4561cd
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false


>  Buildx version 

/usr/bin/docker buildx version
github.com/docker/buildx v0.12.1 30feaa1a915b869ebc2eea6328624b49facd4bfb
Unsupported CI Provider... Using Local Environment as fallback
/usr/bin/git log -1 --pretty=format:%ae
haffter@gmail.com[command]/usr/bin/git symbolic-ref HEAD
fatal: ref HEAD is not a symbolic ref

>  Removing temp folder /tmp/docker-build-push-XVoFAY 


 >  NX   The process '/usr/bin/git' failed with exit code 128

Expected behavior

Here are the logs of the last run of this task, triggered when pushing to main and for the challenge service.

 >  Buildx version 

/usr/bin/docker buildx version
github.com/docker/buildx v0.12.1 30feaa1a915b869ebc2eea6328624b49facd4bfb
Unsupported CI Provider... Using Local Environment as fallback
/usr/bin/git log -1 --pretty=format:%ae
github-actions[bot]@users.noreply.github.com[command]/usr/bin/git symbolic-ref HEAD
refs/heads/main
/usr/bin/git rev-parse HEAD
97a2ef0a32fccc32d9f2c4dcfebf8b8a01d49711

>  Context info 

eventName: push
sha: 97a2ef0a32fccc32d9f2c4dcfebf8b8a01d49711
ref: refs/heads/main
actor: 41898282+github-actions[bot]@users.noreply.github.com
runNumber: 0
runId: 0

Anything else?

No response

Commit ID

No response

Are you developing inside the dev container?

• I am using the dev container

Code of Conduct

• I agree to follow this project's Code of Conduct

[tschaffter]

@mdsage1 bumped into this issue in a PR for these projects:

• openchallenges-organization-service:build-image

I bumped into this issue for these projects:

• openchallenges-api-docs:build-image
• openchallenges-app:build-image
• openchallenges-challenge-service:build-image
• openchallenges-organization-service:build-image
• openchallenges-image-service:build-image

[tschaffter]

The project openchallenges-app ran the build-image task successfully in the CI workflow when pushing to main.

>  Buildx version 

/usr/bin/docker buildx version
github.com/docker/buildx v0.12.1 30feaa1a915b869ebc2eea6328624b49facd4bfb
Unsupported CI Provider... Using Local Environment as fallback
/usr/bin/git log -1 --pretty=format:%ae
pchung@users.noreply.github.com[command]/usr/bin/git symbolic-ref HEAD
refs/heads/main
/usr/bin/git rev-parse HEAD
da6340af0af9d2ce1fd22ad2082fef3ee2fd51f1

[tschaffter]

actions/checkout has always checked out a merge commit during pull request events. This is not a branch, it's a commit that is a merge of the pull request branch and the base. This is so CI can test the merge before it happens. If you are trying to create a pull request to merge into your existing pull request branch then you don't want to do that on the merge commit, instead you should checkout the head_ref. See the documentation here.

Source

[tschaffter]

• detached HEAD actions/checkout#773
• What does "Checkout pull request HEAD commit instead of merge commit" mean? actions/checkout#426 (comment)
• Why a merge commit for pull requests? actions/checkout#504

[tschaffter]

The solution I found is to switch from the detach head to a new branch:

* (HEAD detached at pull/2534/merge) b5977331 Merge 21015cda8e8a29260f5d93574ccaad6377f007e5 into 394b97a1fdd194393b3e8d3e04f7235a5d225ef9
Switched to a new branch 'new-branch'
* new-branch b5977331 Merge 21015cda8e8a29260f5d93574ccaad6377f007e5 into 394b97a1fdd194393b3e8d3e04f7235a5d225ef9

Buildx then runs successfully from this branch.