$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_json.git /var/lib/mock/f39-build-2186557-51358/root/chroot_tmpdir/scmroot/rust-serde_json
Cloning into '/var/lib/mock/f39-build-2186557-51358/root/chroot_tmpdir/scmroot/rust-serde_json'...
$ git fetch origin 051210430236910d42f10868cd898cce7cfbab96:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_json
 * [new ref]         051210430236910d42f10868cd898cce7cfbab96 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0512104 Update to version 1.0.110; Fixes RHBZ#2256357