GitLab CI: you cant pass artifacts between unrelated pipelines, restructure instead

stop trying to bridge pipelines and make it one pipeline. Keep the building job unconditional so it runs on main too, and gate only the deploying job with rules on the main branch. Then pass data with normal artifacts and variables inside that single pipeline run. If you truly need state to survive across pipelines, write it somewhere durable instead: push the version file as a pipeline artifact and fetch it via the API, or tag the commit and read the tag. But for build-then-deploy, the single pipeline with a gated deploy job is the right shape, and it removes the race where the main branch changed between the MR build and the deploy.

Stack Overflow #68179565 (accepted answer): a team tried to pass a BUILD_VERSION variable from a merge-request pipeline to the main-branch pipeline that runs after merge. The accepted answer explains why that cant work: the merge-request pipeline and the main-branch pipeline are unrelated runs, and assuming the merge result equals the MR branch is unsafe, another MR could merge in between or conflicts could resolve differently. The fix is structural: run the building job on every pipeline including main, limit only the deploy job to the main branch, and then artifacts flow naturally within the one pipeline.