$ git clone -n https://src.fedoraproject.org/rpms/rust-signal-hook.git /var/lib/mock/f42-build-side-1-3539465-46565/root/chroot_tmpdir/scmroot/rust-signal-hook
Cloning into '/var/lib/mock/f42-build-side-1-3539465-46565/root/chroot_tmpdir/scmroot/rust-signal-hook'...
$ git fetch origin 97adddddd88f0ca5241f6c9309d8b8033826ccf0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-signal-hook
 * [new ref]         97adddddd88f0ca5241f6c9309d8b8033826ccf0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 97adddd Update to version 0.3.18; Fixes RHBZ#2365310