We'll respond shortly.
A standup of pivots (Sam Coward, Sean Moon, Peter Jaros, and Brent Wheeldon) have recently run into a bug in TeamCity that causes trouble with symlinks when using git.
If you commit symlinks into your repo, TeamCity will not properly transfer these to the build agents. They end up being copied over to the agents as plain text files.
The workaround for this issue is to use Agent-side Checkouts instead of Server-side Checkouts.