$ git clone -n https://src.fedoraproject.org/rpms/perl-Expect-Simple.git /var/lib/mock/f45-build-23413-597/root/chroot_tmpdir/scmroot/perl-Expect-Simple
Cloning into '/var/lib/mock/f45-build-23413-597/root/chroot_tmpdir/scmroot/perl-Expect-Simple'...
$ git fetch origin caf2e90e801315887a6b6a7c23d4be34387d6663:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Expect-Simple
 * [new ref]         caf2e90e801315887a6b6a7c23d4be34387d6663 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at caf2e90 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild