$ git clone -n https://src.fedoraproject.org/rpms/shaderc.git /var/lib/mock/f40-build-788934-135460/root/chroot_tmpdir/scmroot/shaderc
Cloning into '/var/lib/mock/f40-build-788934-135460/root/chroot_tmpdir/scmroot/shaderc'...
$ git fetch origin 66374dd34e7f8d5d62408865e09fa76fa852cdb0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/shaderc
 * [new ref]         66374dd34e7f8d5d62408865e09fa76fa852cdb0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 66374dd Update to 1.3.275.0 SDK