$ git clone -n https://src.fedoraproject.org/rpms/rust-ctor.git /var/lib/mock/f39-build-1445028-32645/root/chroot_tmpdir/scmroot/rust-ctor
Cloning into '/var/lib/mock/f39-build-1445028-32645/root/chroot_tmpdir/scmroot/rust-ctor'...
$ git fetch origin c8e5bd6e6a9a64e4b32a9553f1868a8afb98e234:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-ctor
 * [new ref]         c8e5bd6e6a9a64e4b32a9553f1868a8afb98e234 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c8e5bd6 Update to version 0.2.5; Fixes RHBZ#2240821