$ git clone -n https://src.fedoraproject.org/rpms/perl-Archive-Tar.git /var/lib/mock/f41-build-816905-150476/root/chroot_tmpdir/scmroot/perl-Archive-Tar
Cloning into '/var/lib/mock/f41-build-816905-150476/root/chroot_tmpdir/scmroot/perl-Archive-Tar'...
$ git fetch origin 2f1dcc19e75176db3b15a2563c1eeea0fd087119:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Archive-Tar
 * [new ref]         2f1dcc19e75176db3b15a2563c1eeea0fd087119 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2f1dcc1 Perl 5.40 re-rebuild of bootstrapped packages