$ git clone -n https://src.fedoraproject.org/rpms/perl-Archive-Tar.git /var/lib/mock/f45-build-21808-588/root/chroot_tmpdir/scmroot/perl-Archive-Tar
Cloning into '/var/lib/mock/f45-build-21808-588/root/chroot_tmpdir/scmroot/perl-Archive-Tar'...
$ git fetch origin 27e627ceec573988e6365a6640c95088e8f3d9a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Archive-Tar
 * [new ref]         27e627ceec573988e6365a6640c95088e8f3d9a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 27e627c Perl 5.44 re-rebuild of bootstrapped packages