With current trunk (git.6ca2e0c), there is a problem adding items to the front of the build queue. It can be seen by starting a game, founding a colony, adding a building to the start of the build queue, then pressing "OK". The game hangs completely.
The log (attached) suggest a crash related to the build queue position.
Good catch. The setBuildQueue message was totally borked. Should be fixed in git.1ce7a6b.
Confirmed. Adjusting the build queue works for me with git.1ce7a6b.
Cool. Closing.