prepush: add more precise error messages
Part of the patch is from timeless@mozdev.org
- indicate the branch name where there are multiple heads
- give better advice when hitting a possible race, where new heads are added
between discovery and the call to branchmap(). In that case, asking the user
to merge isn't helpful, since only remote has the changes.
abort: repository a not found!
255
abort: error: Connection refused
255
abort: repository a not found!
255
abort: Permission denied: ../a
255
abort: repository a not found!
255
destination directory: q
abort: destination 'q' is not empty
abort: destination 'a' is not empty
255
adding c
255
dir is still here
repo is gone