$ git clone -n https://src.fedoraproject.org/rpms/geary.git /var/lib/mock/f39-build-1761454-41496/root/chroot_tmpdir/scmroot/geary
Cloning into '/var/lib/mock/f39-build-1761454-41496/root/chroot_tmpdir/scmroot/geary'...
$ git fetch origin 2cfa0848dd439f746fbec2035a4caa958ea1ac43:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/geary
 * [new ref]         2cfa0848dd439f746fbec2035a4caa958ea1ac43 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2cfa084 Update to 44.1