foreign guix offload checklist?

Hi guix, I'm trying to offload a build onto a machine with a foreign distro. I'm getting the following error: $ guix build --system=armhf-linux --no-substitutes hello The following derivations will be built:    /gnu/store/jidb0saw2s3zd1gvnziw064hbb1hxz7y-hello-2.10.drv /gnu/store/hknqainda0ardh

Custom package, specifying cmake source directory?

I'm working on a custom package definition, but when it gets built the cmake files are in "source/src" instead of "source", and so the build system errors out when trying to run cmake. How do I specify the source directory for the cmake build system? From grepping around in the definition for th