$ git clone -n https://src.fedoraproject.org/rpms/perl-Devel-Caller.git /var/lib/mock/f41-build-816464-150205/root/chroot_tmpdir/scmroot/perl-Devel-Caller
Cloning into '/var/lib/mock/f41-build-816464-150205/root/chroot_tmpdir/scmroot/perl-Devel-Caller'...
$ git fetch origin 345a10432be951050dfaa17b48cbfe288630b1f1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Devel-Caller
 * [new ref]         345a10432be951050dfaa17b48cbfe288630b1f1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 345a104 Perl 5.40 rebuild