Yesterday my pullrequest jobs failed with the following output:
11:07:41 > git rev-parse origin/${sha1}^{commit}
11:07:41 > git rev-parse ${sha1}^{co
After lots of research and head breaking. I was receiving the same error and I found out that this error also occurs if you are using a different git path. Make sure you have the correct path. For ex: I replaced C:\Program Files\Git\git-bash.exe with C:\Program Files\Git\bin\git.exe and this resolved the issue.