$ git clone -n http://fedora.riscv.rocks:3000/rpms/xalan-c.git /var/lib/mock/f42-build-862932-171258/root/chroot_tmpdir/scmroot/xalan-c
Cloning into '/var/lib/mock/f42-build-862932-171258/root/chroot_tmpdir/scmroot/xalan-c'...
$ git fetch origin f6b10ab2433f39cf45261670a58537620299595f:KOJI_FETCH_HEAD
From http://fedora.riscv.rocks:3000/rpms/xalan-c
 * [new ref]         f6b10ab2433f39cf45261670a58537620299595f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f6b10ab Newer versions of ICU requires C++17