$ git clone -n https://src.fedoraproject.org/rpms/pre-commit.git /var/lib/mock/f42-build-3285658-41413/root/chroot_tmpdir/scmroot/pre-commit
Cloning into '/var/lib/mock/f42-build-3285658-41413/root/chroot_tmpdir/scmroot/pre-commit'...
$ git fetch origin c05ee258248961fe58021054f2b51ecf306ddf1b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pre-commit
 * [new ref]         c05ee258248961fe58021054f2b51ecf306ddf1b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c05ee25 Add a runtime dependency on git-core