GitLab driver branch fetch is using deprecated GitLab CI environment variables

[nipierre]

Summary / Background

The GitLab driver is using a deprecated environment variable to fetch branch name (namely CI_BUILD_REF_NAME).

Scope

Users using CML on GitLab 16.x.

Assumptions

Should be replaced by either CI_COMMIT_REF_NAME or CI_COMMIT_BRANCH.

Open Questions

Blockers / Dependencies

General Approach

In GitLab CI: cml pr .

Ends up with:

{"level":"error","message":"git,checkout,-B,,c8ea18db3c47a566b6939be8b8c2831dbc5665df\n\t\n\tfatal: '' is not a valid branch name\n","stack":"Error: git,checkout,-B,,c8ea18db3c47a566b6939be8b8c2831dbc5665df\n\t\n\tfatal: '' is not a valid branch name\n\n    at /usr/lib/node_modules/@dvcorg/cml/src/utils.js:38:18\n    at ChildProcess.exithandler (node:child_process:410:5)\n    at ChildProcess.emit (node:events:513:28)\n    at maybeClose (node:internal/child_process:1100:16)\n    at Process.ChildProcess._handle.onexit (node:internal/child_process:304:5)"}

Timelines

I can push a fix by the end of the week.

[dacbd]

@nipierre good catch! @ mention me when you create your PR and I'll prioritize getting it merged and released