$ git clone -n https://src.fedoraproject.org/rpms/rust-cargo-c.git /var/lib/mock/f40-build-763224-122451/root/chroot_tmpdir/scmroot/rust-cargo-c
Cloning into '/var/lib/mock/f40-build-763224-122451/root/chroot_tmpdir/scmroot/rust-cargo-c'...
$ git fetch origin 3ac5fef4259172a253c0c9f3f0305ba7c3686c9d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cargo-c
 * [new ref]         3ac5fef4259172a253c0c9f3f0305ba7c3686c9d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3ac5fef Update to version 0.9.28+cargo-0.75.0; Fixes RHBZ#2250815