$ git clone -n https://src.fedoraproject.org/rpms/gcc.git /var/lib/mock/f45-build-150-71/root/chroot_tmpdir/scmroot/gcc
Cloning into '/var/lib/mock/f45-build-150-71/root/chroot_tmpdir/scmroot/gcc'...
$ git fetch origin f1668b58c9e741961539c976e76286d1eebf8278:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gcc
 * [new ref]         f1668b58c9e741961539c976e76286d1eebf8278 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f1668b5 16.1.1-4