$ git clone -n https://src.fedoraproject.org/rpms/rust-oxipng.git /var/lib/mock/f42-build-side-1-3586032-46913/root/chroot_tmpdir/scmroot/rust-oxipng
Cloning into '/var/lib/mock/f42-build-side-1-3586032-46913/root/chroot_tmpdir/scmroot/rust-oxipng'...
$ git fetch origin 29e3b2d65c211bc266e67451a5f05f45b3862e34:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-oxipng
 * [new ref]         29e3b2d65c211bc266e67451a5f05f45b3862e34 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 29e3b2d Update to version 9.1.5; Fixes RHBZ#2362416