$ git clone -n https://src.fedoraproject.org/rpms/perl-Sys-Syscall.git /var/lib/mock/f41-build-1639688-24158/root/chroot_tmpdir/scmroot/perl-Sys-Syscall
Cloning into '/var/lib/mock/f41-build-1639688-24158/root/chroot_tmpdir/scmroot/perl-Sys-Syscall'...
$ git fetch origin c150b478ed6058427f01ce2b3697059b4a1c86a6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Sys-Syscall
 * [new ref]         c150b478ed6058427f01ce2b3697059b4a1c86a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c150b47 Eliminate use of obsolete %patchN syntax (#2283636)