[bug#39021] [PATCH 1/2 v2] build-system/go: Allow providing additional build flags

["Jakub Kądziołka" <kuba@kadziolka.net>]

* guix/build-system/go.scm (build-flags): New argument.
* guix/build/go-build-system.scm (build): Use apply to pass the
  additional arguments to invoke.
---
I have discovered a bug when testing v1 of this patch locally - some Go
packages have been failing to build due to a quoting mishap. This is now
fixed.

Diff between patches:
-                   (build-flags '())
+                   (build-flags ''())
[this note should be automatically removed by git am]
---
 guix/build-system/go.scm       | 3 +++
 guix/build/go-build-system.scm | 7 ++++---
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/guix/build-system/go.scm b/guix/build-system/go.scm
index 1b916af8f9..f8ebaefb27 100644
--- a/guix/build-system/go.scm
+++ b/guix/build-system/go.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2016 Petter <petter@mykolab.ch>
 ;;; Copyright © 2017 Leo Famulari <leo@famulari.name>
+;;; Copyright © 2020 Jakub Kądziołka <kuba@kadziolka.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -82,6 +83,7 @@
                    (install-source? #t)
                    (import-path "")
                    (unpack-path "")
+                   (build-flags ''())
                    (tests? #t)
                    (allow-go-reference? #f)
                    (system (%current-system))
@@ -109,6 +111,7 @@
                 #:install-source? ,install-source?
                 #:import-path ,import-path
                 #:unpack-path ,unpack-path
+                #:build-flags ,build-flags
                 #:tests? ,tests?
                 #:allow-go-reference? ,allow-go-reference?
                 #:inputs %build-inputs)))
diff --git a/guix/build/go-build-system.scm b/guix/build/go-build-system.scm
index 4bc0156a88..49887848f6 100644
--- a/guix/build/go-build-system.scm
+++ b/guix/build/go-build-system.scm
@@ -2,6 +2,7 @@
 ;;; Copyright © 2016 Petter <petter@mykolab.ch>
 ;;; Copyright © 2017, 2019 Leo Famulari <leo@famulari.name>
 ;;; Copyright © 2019 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;; Copyright © 2020 Jakub Kądziołka <kuba@kadziolka.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -209,18 +210,18 @@ unpacking."
                 (_ #f))
               inputs))))
 
-(define* (build #:key import-path #:allow-other-keys)
+(define* (build #:key import-path build-flags #:allow-other-keys)
   "Build the package named by IMPORT-PATH."
   (with-throw-handler
     #t
     (lambda _
-      (invoke "go" "install"
+      (apply invoke "go" "install"
               "-v" ; print the name of packages as they are compiled
               "-x" ; print each command as it is invoked
               ;; Respectively, strip the symbol table and debug
               ;; information, and the DWARF symbol table.
               "-ldflags=-s -w"
-              import-path))
+              `(,@build-flags ,import-path)))
     (lambda (key . args)
       (display (string-append "Building '" import-path "' failed.\n"
                               "Here are the results of `go env`:\n"))
-- 
2.25.0