When configure for lustre runs it decides the availability of spl/zfs by looking at the host node rather than looking at the build environment.

This means that the build node has to have spl/zfs installed even though the actually building of lustre-zfs uses the build environment which has a spl/zfs development environment available.

I don't think this make sense, it should not be a requirement for the build host to have every feature installed that the target build is going to contain.

This has caused problems here; TT-391; when our build nodes where upgraded.