$ git clone -n https://src.fedoraproject.org/rpms/perl-Bit-Vector.git /var/lib/mock/f45-build-21884-588/root/chroot_tmpdir/scmroot/perl-Bit-Vector
Cloning into '/var/lib/mock/f45-build-21884-588/root/chroot_tmpdir/scmroot/perl-Bit-Vector'...
$ git fetch origin 531259b5d2a800ab1ea0e386c46b82d4a28c1e04:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Bit-Vector
 * [new ref]         531259b5d2a800ab1ea0e386c46b82d4a28c1e04 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 531259b Perl 5.44 rebuild