$ git clone -n https://src.fedoraproject.org/rpms/perl-String-Base.git /var/lib/mock/f45-build-26269-616/root/chroot_tmpdir/scmroot/perl-String-Base
Cloning into '/var/lib/mock/f45-build-26269-616/root/chroot_tmpdir/scmroot/perl-String-Base'...
$ git fetch origin 2c2d40c6b8a44033629a57f659f03e53e3a4cfdb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-String-Base
 * [new ref]         2c2d40c6b8a44033629a57f659f03e53e3a4cfdb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2c2d40c Perl 5.44 rebuild