$ git clone -n https://src.fedoraproject.org/rpms/rust-peg.git /var/lib/mock/f41-build-1197751-22354/root/chroot_tmpdir/scmroot/rust-peg
Cloning into '/var/lib/mock/f41-build-1197751-22354/root/chroot_tmpdir/scmroot/rust-peg'...
$ git fetch origin a0e81e9509dbf17d5519ff97405be0f31d503573:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-peg
 * [new ref]         a0e81e9509dbf17d5519ff97405be0f31d503573 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a0e81e9 Update to version 0.8.3; Fixes RHBZ#2277533