CODEOWNERS "Last Match Wins" Not Working for Nested Directory Patterns

Summary

GitLab's CODEOWNERS file does not correctly apply the "last match wins" rule when the same directory path is defined multiple times with different owners.

Expected Behavior

According to GitLab documentation:

When a file or directory matches multiple entries in the CODEOWNERS file, the users from last pattern matching the file or directory are used.

Given a CODEOWNERS file with duplicate paths:

packages/client/docker/ @team-a
packages/client/docker/ @team-b

Files in packages/client/docker/ should be owned by @team-b (the last matching entry).

Actual Behavior

GitLab shows @team-a (the first matching entry) as the code owner, not the last one.

Steps to Reproduce

  1. Create a CODEOWNERS file with duplicate directory entries:
packages/client/docker/ @team-a
# ... other entries ...
packages/client/docker/ @team-b

  1. View code owners for any file in packages/client/docker/ (e.g., packages/client/docker/Dockerfile)

  2. Observed: GitLab shows @team-a as the code owner

  3. Expected: GitLab should show @team-b as the code owner (last match wins)

Environment

  • GitLab version: 18.7 Release

Impact

This prevents implementing layered ownership patterns where multiple teams need to be involved in code reviews, with the last defined team having final approval authority. The "last match wins" rule is fundamental to CODEOWNERS functionality and is inconsistent with documented behavior.

Edited by Cengiz Krämer