$ git clone -n https://src.fedoraproject.org/rpms/golang-modernc-libc.git /var/lib/mock/f45-build-20269-569/root/chroot_tmpdir/scmroot/golang-modernc-libc
Cloning into '/var/lib/mock/f45-build-20269-569/root/chroot_tmpdir/scmroot/golang-modernc-libc'...
$ git fetch origin 67aafc1b7f84261bba87c56513ca3830d58440f6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-modernc-libc
 * [new ref]         67aafc1b7f84261bba87c56513ca3830d58440f6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 67aafc1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild