$ git clone -n https://src.fedoraproject.org/rpms/gsl.git /var/lib/mock/f41-build-1028419-18355/root/chroot_tmpdir/scmroot/gsl
Cloning into '/var/lib/mock/f41-build-1028419-18355/root/chroot_tmpdir/scmroot/gsl'...
$ git fetch origin 672a7fbcf914525252ce3b1c114823a9a3972014:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gsl
 * [new ref]         672a7fbcf914525252ce3b1c114823a9a3972014 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 672a7fb Eliminate use of obsolete %patchN syntax (#2283636)