Packaging Golang programs

[Formbi]

Hi

I'm trying to package Protonmail's proton-bridge, which is written in Go. In 
most cases, it's quite easy to import a package or write the definition 
manually. However, some packages are made of sub-packages and the build system 
says, for example:

can't load package: package golang.org/x/mobile: no Go files in (…)

Those packages are referenced as whole, though. If the sub-packages (with 
#:unpack-path) are needed, they don't really work either. For example 
github.com/shurcooL/httpfs/vfsutil in the test suite can't find itself:

package github.com/shurcool/httpfs/vfsutil_test
        imports github.com/shurcooL/httpfs/vfsutil: cannot find package 
"github.com/shurcooL/httpfs/vfsutil" in any of:
        
/gnu/store/y5rwacd5l4q26pxis28wsmswj2603hkw-go-1.14.15/src/github.com/shurcooL/httpfs/vfsutil
 (from $GOROOT)
        
/tmp/guix-build-go-github-com-shurcool-httpfs-vfsutil-0.0.0-20190707220628-8d4bc4ba7749.drv-0/src/github.com/shurcooL/httpfs/vfsutil
 (from $GOPATH)
FAIL    github.com/shurcool/httpfs/vfsutil [setup failed]
FAIL

Disabling the tests doesn't suffice here, because after it «builds», it can't 
be found by a package which needs it. Could you please give me some directions?

Kind regards.