$ git clone -n https://src.fedoraproject.org/rpms/perl-Scalar-String.git /var/lib/mock/f45-build-26194-616/root/chroot_tmpdir/scmroot/perl-Scalar-String
Cloning into '/var/lib/mock/f45-build-26194-616/root/chroot_tmpdir/scmroot/perl-Scalar-String'...
$ git fetch origin f985b88a3632ce6f2aaff32ad409dcdb6723d316:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Scalar-String
 * [new ref]         f985b88a3632ce6f2aaff32ad409dcdb6723d316 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f985b88 Perl 5.44 rebuild