guix: scripts: Add GUIX_BUILD_OPTIONS environment handling.

* doc/guix.texi (Invoking guix build): Mention 'GUIX_BUILD_OPTIONS'.
* guix/scripts/archive.scm: (append args (environment-build-options)).
* guix/scripts/build.scm: Ditto.
* guix/scripts/environment.scm: Ditto.
* guix/scripts/package.scm: Ditto.
* guix/scripts/system.scm: Ditto.
* guix/ui.scm (environment-build-options): New function.
* guix/utils.scm (arguments-from-environment-variable): New function.
* tests/guix-build.sh: Add tests.
* test-env.in: Unset GUIX_BUILD_OPTIONS.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

7 files changed, 25 insertions, 5 deletions

diff --git a/guix/scripts/archive.scm b/guix/scripts/archive.scm
index 84904e29da..29a3ad15a7 100644
--- a/guix/scripts/archive.scm
+++ b/guix/scripts/archive.scm
@@ -293,7 +293,8 @@ the input port."
 (define (guix-archive . args)
   (define (parse-options)
     ;; Return the alist of option values.
-    (args-fold* args %options
+    (args-fold* (append args (environment-build-options))
+                %options
                 (lambda (opt name arg result)
                   (leave (_ "~A: unrecognized option~%") name))
                 (lambda (arg result)
diff --git a/guix/scripts/build.scm b/guix/scripts/build.scm
index b4aa33b3a0..76a743f0b3 100644
--- a/guix/scripts/build.scm
+++ b/guix/scripts/build.scm
@@ -401,7 +401,8 @@ arguments with packages that use the specified source."
 (define (guix-build . args)
   (define (parse-options)
     ;; Return the alist of option values.
-    (args-fold* args %options
+    (args-fold* (append args (environment-build-options))
+                %options
                 (lambda (opt name arg result)
                   (leave (_ "~A: unrecognized option~%") name))
                 (lambda (arg result)
diff --git a/guix/scripts/environment.scm b/guix/scripts/environment.scm
index 81bad963f6..a309dfa362 100644
--- a/guix/scripts/environment.scm
+++ b/guix/scripts/environment.scm
@@ -213,7 +213,8 @@ packages."
 ;; Entry point.
 (define (guix-environment . args)
   (define (parse-options)
-    (args-fold* args %options
+    (args-fold* (append args (environment-build-options))
+                %options
                 (lambda (opt name arg result)
                   (leave (_ "~A: unrecognized option~%") name))
                 (lambda (arg result)
diff --git a/guix/scripts/package.scm b/guix/scripts/package.scm
index 3a72053766..9ff4d17bf4 100644
--- a/guix/scripts/package.scm
+++ b/guix/scripts/package.scm
@@ -668,7 +668,8 @@ removed from MANIFEST."
 (define (guix-package . args)
   (define (parse-options)
     ;; Return the alist of option values.
-    (args-fold* args %options
+    (args-fold* (append args (environment-build-options))
+                %options
                 (lambda (opt name arg result arg-handler)
                   (leave (_ "~A: unrecognized option~%") name))
                 (lambda (arg result arg-handler)
diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 398a5a371b..8ea77e4f3c 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -467,7 +467,8 @@ Build the operating system declared in FILE according to ACTION.\n"))
 (define (guix-system . args)
   (define (parse-options)
     ;; Return the alist of option values.
-    (args-fold* args %options
+    (args-fold* (append args (environment-build-options))
+                %options
                 (lambda (opt name arg result)
                   (leave (_ "~A: unrecognized option~%") name))
                 (lambda (arg result)
diff --git a/guix/ui.scm b/guix/ui.scm
index 69b073da50..c77e04172e 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -64,6 +64,7 @@
             string->generations
             string->duration
             args-fold*
+            environment-build-options
             run-guix-command
             program-name
             guix-warning-port
@@ -712,6 +713,10 @@ reporting."
       (leave (_ "invalid argument: ~a~%")
              (apply format #f msg args)))))
 
+(define (environment-build-options)
+  "Return additional build options passed as environment variables."
+  (arguments-from-environment-variable "GUIX_BUILD_OPTIONS"))
+
 (define (show-guix-usage)
   (format (current-error-port)
           (_ "Try `guix --help' for more information.~%"))
diff --git a/guix/utils.scm b/guix/utils.scm
index 9b802b6fb3..d0d2e8a3d4 100644
--- a/guix/utils.scm
+++ b/guix/utils.scm
@@ -72,6 +72,7 @@
             package-name->name+version
             string-tokenize*
             string-replace-substring
+            arguments-from-environment-variable
             file-extension
             file-sans-extension
             call-with-temporary-output-file
@@ -627,6 +628,15 @@ REPLACEMENT."
                        (substring str start index)
                        pieces))))))))
 
+(define (arguments-from-environment-variable variable)
+  "Retrieve value of environment variable denoted by string VARIABLE in the
+form of a list of strings (`char-set:graphic' tokens) suitable for consumption
+by `args-fold', if VARIABLE is defined, otherwise return an empty list."
+  (let ((env (getenv variable)))
+    (if env
+        (string-tokenize env char-set:graphic)
+        '())))
+
 (define (call-with-temporary-output-file proc)
   "Call PROC with a name of a temporary file and open output port to that
 file; close the file and delete it when leaving the dynamic extent of this