build/go: Replace symlinks with a copy of the file.

* guix/build/go-build-system.scm (fix-embed-files): New procedure.
(%standard-phases): Add 'fix-embed-files after 'unpack.
* guix/build-system/go.scm (#:embed-files): New key parameter.
* doc/guix.texi: (go-build-system): Document a new key.

Co-authored-by: Sharlatan Hellseher <sharlatanus@gmail.com>
Change-Id: I27bc46fa1a3f4675ff73b6cba4ef5c3d177c22b1

3 files changed, 41 insertions, 2 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 789e153189..8f65387e92 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -132,6 +132,8 @@ Copyright @copyright{} 2024 Denis 'GNUtoo' Carikli@*
 Copyright @copyright{} 2024 Fabio Natali@*
 Copyright @copyright{} 2024 Arnaud Daby-Seesaram@*
 Copyright @copyright{} 2024 Nigko Yerden@*
+Copyright @copyright{} 2024 Troy Figiel@*
+Copyright @copyright{} 2024 Sharlatan Hellseher@*
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -9588,6 +9590,11 @@ the test binary.  Build, test and test binary flags can be provided as
 @code{#:test-flags} parameter, default is @code{'()}.  See @code{go help
 test} and @code{go help testflag} for more details.
 
+The key @code{#:embed-files}, default is @code{'()}, provides a list of
+future embedded files or regexps matching files.  They will be copied to
+build directory after @code{unpack} phase.  See
+@url{https://pkg.go.dev/embed} for more details.
+
 @end defvar
 
 @defvar glib-or-gtk-build-system
diff --git a/guix/build-system/go.scm b/guix/build-system/go.scm
index e6e8b84e48..97581a14c6 100644
--- a/guix/build-system/go.scm
+++ b/guix/build-system/go.scm
@@ -6,6 +6,8 @@
 ;;; Copyright © 2021, 2023 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2021 Sarah Morgensen <iskarian@mgsn.dev>
 ;;; Copyright © 2024 Christina O'Donnell <cdo@mutix.org>
+;;; Copyright © 2024 Troy Figiel <troy@troyfigiel.com>
+;;; Copyright © 2024 Sharlatan Hellseher <sharlatanus@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -197,6 +199,7 @@ commit hash and its date rather than a proper release tag."
                    (outputs '("out"))
                    (search-paths '())
                    (install-source? #t)
+                   (embed-files ''())
                    (import-path "")
                    (unpack-path "")
                    (build-flags ''())
@@ -226,6 +229,7 @@ commit hash and its date rather than a proper release tag."
                     #:substitutable? #$substitutable?
                     #:goarch #$goarch
                     #:goos #$goos
+                    #:embed-files #$embed-files
                     #:search-paths '#$(sexp->gexp
                                        (map search-path-specification->sexp
                                             search-paths))
@@ -264,6 +268,7 @@ commit hash and its date rather than a proper release tag."
                          (system (%current-system))
                          (goarch (first (go-target target)))
                          (goos (last (go-target target)))
+                         (embed-files ''())
                          (guile #f)
                          (imported-modules %go-build-system-modules)
                          (modules '((guix build go-build-system)
@@ -297,6 +302,7 @@ commit hash and its date rather than a proper release tag."
                     #:target #$target
                     #:goarch #$goarch
                     #:goos #$goos
+                    #:embed-files #$embed-files
                     #:inputs %build-target-inputs
                     #:native-inputs %build-host-inputs
                     #:search-paths '#$(map search-path-specification->sexp
diff --git a/guix/build/go-build-system.scm b/guix/build/go-build-system.scm
index 3f0f5700a1..14cb5ae687 100644
--- a/guix/build/go-build-system.scm
+++ b/guix/build/go-build-system.scm
@@ -4,10 +4,12 @@
 ;;; Copyright © 2019 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 ;;; Copyright © 2020 Jack Hill <jackhill@jackhill.us>
 ;;; Copyright © 2020 Jakub Kądziołka <kuba@kadziolka.net>
-;;; Copyright © 2020, 2021, 2023 Efraim Flashner <efraim@flashner.co.il>
+;;; Copyright © 2020, 2021, 2023, 2024 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2021 Sarah Morgensen <iskarian@mgsn.dev>
 ;;; Copyright © 2024 Ekaitz Zarraga <ekaitz@elenq.tech>
 ;;; Copyright © 2024 Picnoir <picnoir@alternativebit.fr>
+;;; Copyright © 2024 Troy Figiel <troy@troyfigiel.com>
+;;; Copyright © 2024 Sharlatan Hellseher <sharlatanus@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -28,8 +30,9 @@
   #:use-module ((guix build gnu-build-system) #:prefix gnu:)
   #:use-module (guix build union)
   #:use-module (guix build utils)
-  #:use-module (ice-9 match)
+  #:use-module (ice-9 format)
   #:use-module (ice-9 ftw)
+  #:use-module (ice-9 match)
   #:use-module (srfi srfi-1)
   #:use-module (rnrs io ports)
   #:use-module (rnrs bytevectors)
@@ -201,6 +204,28 @@ dependencies, so it should be self-contained."
     (delete-file-recursively tmpdir))
   #t)
 
+(define* (fix-embed-files #:key embed-files #:allow-other-keys)
+  "Golang can't determine the valid directory of the module of embed file
+which is symlinked during setup environment phase, but easy resolved after
+coping file from the store to the build directory of the current package. Take
+a list of files or regexps matching files from EMBED-FILES paramter, failover
+to 'editions_defaults.binpb' which is a part of <github.com/golang/protobuf>."
+  ;; see details in Golang source:
+  ;;
+  ;; - URL: <https://github.com/golang/go/blob/>
+  ;; - commit: 82c14346d89ec0eeca114f9ca0e88516b2cda454
+  ;; - file: src/cmd/go/internal/load/pkg.go#L2059
+  (let ((embed-files (format #f "^(~{~a|~}~a)$"
+                             embed-files
+                             "editions_defaults.binpb")))
+    (for-each (lambda (file)
+                (when (eq? (stat:type (lstat file))
+                           'symlink)
+                  (let ((file-store-path (readlink file)))
+                    (delete-file file)
+                    (copy-recursively file-store-path file))))
+              (find-files "src" embed-files))))
+
 (define* (unpack #:key source import-path unpack-path #:allow-other-keys)
   "Relative to $GOPATH, unpack SOURCE in UNPACK-PATH, or IMPORT-PATH when
 UNPACK-PATH is unset.  If the SOURCE archive has a single top level directory,
@@ -321,6 +346,7 @@ the standard install-license-files phase to first enter the correct directory."
     (delete 'patch-generated-file-shebangs)
     (add-before 'unpack 'setup-go-environment setup-go-environment)
     (replace 'unpack unpack)
+    (add-after 'unpack 'fix-embed-files fix-embed-files)
     (replace 'build build)
     (replace 'check check)
     (replace 'install install)