$ git clone -n https://src.fedoraproject.org/rpms/perl-File-Unpack2.git /var/lib/mock/f45-build-23598-598/root/chroot_tmpdir/scmroot/perl-File-Unpack2
Cloning into '/var/lib/mock/f45-build-23598-598/root/chroot_tmpdir/scmroot/perl-File-Unpack2'...
$ git fetch origin a6186f3663dba15c5f76d37778c7ce76cf234fa4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-File-Unpack2
 * [new ref]         a6186f3663dba15c5f76d37778c7ce76cf234fa4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a6186f3 Update to 2.0 upstream release