Building a go package with no top level go files

[Reza Housseini]

Hi Guixers

I am in the process of packaging gopass and got stuck with the package

(define-public go-github-com-protonmail-go-crypto
  (package
    (name "go-github-com-protonmail-go-crypto")
    (version "1.4.0")
    (source
     (origin
       (method git-fetch)
       (uri (git-reference
             (url "https://github.com/ProtonMail/go-crypto";)
             (commit (string-append "v" version))))
       (file-name (git-file-name name version))
       (sha256
        (base32 "19g0vhg83yaa81l0qhlq4pbkid7nv57p7s5kbmysbaf60jmv7887"))))
    (build-system go-build-system)
    (arguments
     (list
      #:skip-build? #t
      #:import-path "github.com/protonmail/go-crypto"))
    (propagated-inputs (list go-github-com-cloudflare-circl
                             go-golang-org-x-crypto))
    (home-page "https://github.com/protonmail/go-crypto";)
    (synopsis "Go Cryptography")
    (description
     "This repository holds supplementary Go cryptography libraries.")
    (license license:bsd-3)))

It has no go files at te top level directory and will fail in the build
phase with "No Go files" error. I added the #:skip-build #t flag to
overcome this but the package then obviously fails in the check phase.
What is the correct thing to do in such a case? I have no clue about go
and could not find any build instructions elsewhere.

Thanks for the help,
Best,
Reza