Possible race condition during git global variable setting

[tsalo]

The home's gitconfig file "already exists" when it's being locked by jobs submitted at exactly the same time.

[tsalo]

Since this happens at the very beginning of the workflow, if we just figure out how to delay the start of the workflows relative to when the jobs move out of the queue, it should be fine.

[akimbler]

This has always been an issue in run() IMO, we should be using Popen.wait() to prevent processes from potentially starting before the previous process is finished, similar to the first comment in https://stackoverflow.com/questions/4417546/constantly-print-subprocess-output-while-process-is-running