$ git clone -n https://src.fedoraproject.org/rpms/perl-Test-Simple.git /var/lib/mock/eln-build-side-114847-60995249-6587417/root/chroot_tmpdir/scmroot/perl-Test-Simple
Cloning into '/var/lib/mock/eln-build-side-114847-60995249-6587417/root/chroot_tmpdir/scmroot/perl-Test-Simple'...
$ git fetch origin 652e4e08d072c43b970d78396cf8fef6a15681f3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Test-Simple
 * [new ref]         652e4e08d072c43b970d78396cf8fef6a15681f3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 652e4e0 Perl 5.42 re-rebuild of bootstrapped packages