"Unknown" committers in the Committers Report

Symptoms

Commiters Report shows some commiters as "unknown".

Cause

When TeamCity detects a commit, it tries to link it to an existing TeamCity user based on the configured VCS usernames and username patterns. If a commit can't be automatically matched to an existing TeamCity user, then such a commit is linked to an "unknown" committer.

This may happen in the following cases:

• A committer has different VCS usernames across multiple VCS services (e.g. GitHub, GitLab, Bitbucket).
• A committer has different VCS usernames across multiple environments (e.g., Git on a personal laptop and office PC).
• These extra usernames are not configured in TeamCity, or the committer does not have an associated user account in TeamCity.

Resolution

To avoid "unknown" committers consuming your committer slots, it is recommended that you register all committers as TeamCity users and configure each user's VCS username, as described in the documentation.