$ git clone -n https://src.fedoraproject.org/rpms/rust-fixed.git /var/lib/mock/f41-build-side-1-2923769-34983/root/chroot_tmpdir/scmroot/rust-fixed
Cloning into '/var/lib/mock/f41-build-side-1-2923769-34983/root/chroot_tmpdir/scmroot/rust-fixed'...
$ git fetch origin ae066c7536f4b89d4a559e0ddae669487ca4b2f5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-fixed
 * [new ref]         ae066c7536f4b89d4a559e0ddae669487ca4b2f5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ae066c7 Fix syntax for skipping doctests to resolve build issues with Rust 1.80+