$ git clone -n https://src.fedoraproject.org/rpms/python-google-cloud-build.git /var/lib/mock/f39-build-1853885-42379/root/chroot_tmpdir/scmroot/python-google-cloud-build
Cloning into '/var/lib/mock/f39-build-1853885-42379/root/chroot_tmpdir/scmroot/python-google-cloud-build'...
$ git fetch origin f2aaebfd06624b8ffb8ce8a55955986f5c05debf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-google-cloud-build
 * [new ref]         f2aaebfd06624b8ffb8ce8a55955986f5c05debf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f2aaebf Update to 3.21.0 rhbz#2247618