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{"@context":"https://schema.org","@type":"QAPage","mainEntity":{"@type":"Question","name":"Error when triggering a pipeline for a merge request: \"The resulting pipeline would have been empty\"","text":"
Description of the problem, including code/CLI snippet
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I’m trying to trigger a pipeline for a merge request using the python-gitlab package, but I’m encountering a 400 error with the message: \"The resulting pipeline would have been empty.\" My GitLab CI configuration does not include any rules for the job, so I’m unsure why this error is occurring.
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Here’s the code I’m using:
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import gitlab\nfrom .constants import URL, TOKEN, PROJECT_ID, MR_ID\n\ngl = gitlab.Gitlab(url=URL, private_token=TOKEN)\n\nresponse = gl.http_request(\n    \"POST\",\n    f\"/projects/{PROJECT_ID}/merge_requests/{MR_ID}/pipelines\",\n    timeout=60,\n    retry_transient_errors=True,\n)\n\nprint(response)\n
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And here’s my .gitlab-ci.yml configuration:
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pre-commit:\n  image: python:3.12-bookworm\n\n  before_script:\n    - apt update\n    - apt install -y --no-install-recommends pipx\n    - PATH=\"/root/.local/bin:$PATH\"\n    - pipx install pre-commit\n\n  script:\n    - pre-commit run --all-files\n
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Expected Behavior
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The pipeline should be triggered successfully, and the pre-commit job defined in the .gitlab-ci.yml file should run.
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Actual Behavior
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The pipeline fails to trigger, and I receive the following error:
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Traceback (most recent call last):\n  File \"/Users/neXeacon/Desktop/marge-bot/test.py\", line 7, in <module>\n    response = gl.http_request(\n        \"POST\",\n        f\"/projects/{PROJECT_ID}/merge_requests/{MR_ID}/pipelines\",\n        timeout=60,\n        retry_transient_errors=True,\n    )\n  File \"/Users/neXeacon/Desktop/marge-bot/venv/lib/python3.13/site-packages/gitlab/client.py\", line 773, in http_request\n    raise gitlab.exceptions.GitlabHttpError(\ngitlab.exceptions.GitlabHttpError: 400: {'base': ['The resulting pipeline would have been empty. Review the rules configuration for the relevant jobs.']}\n
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Specifications
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python-gitlab version: 5.3.0
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Gitlab server version (or gitlab.com): 8.7.1
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","upvoteCount":1,"answerCount":2,"acceptedAnswer":{"@type":"Answer","text":"
This doesn't sound like a python-gitlab issue to me.
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Please look at: https://docs.gitlab.com/ee/api/merge_requests.html#create-merge-request-pipeline
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From the first part of the docs there it says:
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Create a new pipeline for a merge request. A pipeline created from this endpoint doesn’t run a regular branch/tag pipeline. To create jobs, configure .gitlab-ci.yml with only: [merge_requests].
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Also look at https://docs.gitlab.com/ee/ci/yaml/  and search for merge_requests. Looks like it is required to have in the .gitlab-ci.yml a only: merge_requests in your config.
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Any reason to not use: https://python-gitlab.readthedocs.io/en/stable/gl_objects/merge_requests.html#merge-request-pipelines ?
","upvoteCount":1,"url":"https://github.com/python-gitlab/python-gitlab/discussions/3076#discussioncomment-11719234"}}}