$ git clone -n https://src.fedoraproject.org/rpms/rust-clang-ast.git /var/lib/mock/f39-build-2210136-52172/root/chroot_tmpdir/scmroot/rust-clang-ast
Cloning into '/var/lib/mock/f39-build-2210136-52172/root/chroot_tmpdir/scmroot/rust-clang-ast'...
$ git fetch origin e6bc80ea5a0170ccf39168527317d12ff399428c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-clang-ast
 * [new ref]         e6bc80ea5a0170ccf39168527317d12ff399428c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e6bc80e Update to version 0.1.22; Fixes RHBZ#2256505