[bug#36563] [PATCH] guix: Add directory to channel.

[Jan Nieuwenhuizen]

Hi!

I commonly use a "guix/" subdirectory in upstream that contains updated
or modified packages.  The toplevel `guix.scm' then uses those package
definitions.

It would be nice if I could use that "guix/" subdirectory directly in a
channel.  This means a channel definition should look in a subdirectory
only: often an upstream source archive contains .scm files that do not
compile (guix.scm, build-aux/*.scm, etc.)

WDYT?

Greetings,
janneke

>From cf85280211ff0060b5283dc5a53cb15ee09a7998 Mon Sep 17 00:00:00 2001
From: Jan Nieuwenhuizen <address@hidden>
Date: Tue, 9 Jul 2019 21:01:11 +0200
Subject: [PATCH] guix: Add directory to channel.

Typical use

    (cons* (channel
            (name 'mes)
            (url "https://git.savannah.gnu.org/git/mes.git";)
            (directory "guix")
            (branch "wip"))
           %default-channels)

* guix/channels.scm (<channel>): Add directory.
(read-channel-metadata): Fill directory slot.
(checkout->channel-instance): Add #:directory parameter.  Update callers.
(standard-module-derivation): Add directory parameter.  Update callers.
(build-channel-instance): Provide directory argument.
---
 guix/channels.scm | 58 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 37 insertions(+), 21 deletions(-)

diff --git a/guix/channels.scm b/guix/channels.scm
index e6bb9b891b..bd64906832 100644
--- a/guix/channels.scm
+++ b/guix/channels.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2018, 2019 Ludovic Courtès <address@hidden>
 ;;; Copyright © 2018 Ricardo Wurmus <address@hidden>
+;;; Copyright © 2019 Jan (janneke) Nieuwenhuizen <address@hidden>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -50,6 +51,7 @@
             channel-branch
             channel-commit
             channel-location
+            channel-directory
 
             %default-channels
             guix-channel?
@@ -86,7 +88,8 @@
   (branch    channel-branch (default "master"))
   (commit    channel-commit (default #f))
   (location  channel-location
-             (default (current-source-location)) (innate)))
+             (default (current-source-location)) (innate))
+  (directory channel-directory (default #f)))
 
 (define %default-channels
   ;; Default list of channels.
@@ -141,7 +144,8 @@ file."
                         (name name)
                         (branch branch)
                         (url url)
-                        (commit (get 'commit))))))
+                        (commit (get 'commit))
+                        (directory (get 'directory))))))
                  dependencies))))))
 
 (define (channel-instance-dependencies instance)
@@ -205,13 +209,16 @@ of previously processed channels."
 
 (define* (checkout->channel-instance checkout
                                      #:key commit
-                                     (url checkout) (name 'guix))
+                                     (url checkout)
+                                     (name 'guix)
+                                     directory)
   "Return a channel instance for CHECKOUT, which is assumed to be a checkout
 of COMMIT at URL.  Use NAME as the channel name."
   (let* ((commit  (or commit (make-string 40 #\0)))
          (channel (channel (name name)
                            (commit commit)
-                           (url url))))
+                           (url url)
+                           (directory directory))))
     (channel-instance channel commit checkout)))
 
 (define %self-build-file
@@ -225,11 +232,12 @@ of COMMIT at URL.  Use NAME as the channel name."
   ;; place a set of compiled Guile modules in ~/.config/guix/latest.
   1)
 
-(define (standard-module-derivation name source core dependencies)
+(define (standard-module-derivation name source directory core dependencies)
   "Return a derivation that builds with CORE, a Guix instance, the Scheme
-modules in SOURCE and that depend on DEPENDENCIES, a list of lowerable
-objects.  The assumption is that SOURCE contains package modules to be added
-to '%package-module-path'."
+modules in SOURCE or if DIRECTORY in SOURCE/DIRECTORY and that depend on
+DEPENDENCIES, a list of lowerable objects.  The assumption is that SOURCE or
+SOURCE/DIRECTORY contains package modules to be added to
+'%package-module-path'."
   ;; FIXME: We should load, say SOURCE/.guix-channel.scm, which would allow
   ;; channel publishers to specify things such as the sub-directory where .scm
   ;; files live, files to exclude from the channel, preferred substitute URLs,
@@ -253,20 +261,27 @@ to '%package-module-path'."
             (string-append #$output "/share/guile/site/"
                            (effective-version)))
 
-          (compile-files #$source go
-                         (find-files #$source "\\.scm$"))
-          (mkdir-p (dirname scm))
-          (symlink #$source scm)
+          (let* ((subdir (if #$directory
+                             (string-append "/" #$directory)
+                             ""))
+                 (dir (string-append #$source subdir)))
+            (compile-files dir go
+                           (warn 'files (find-files dir "\\.scm$")))
+            (mkdir-p (dirname scm))
+            (symlink (string-append #$source subdir) scm))
+
           scm)))
 
   (gexp->derivation-in-inferior name build core))
 
 (define* (build-from-source name source
                             #:key core verbose? commit
-                            (dependencies '()))
+                            (dependencies '())
+                            directory)
   "Return a derivation to build Guix from SOURCE, using the self-build script
 contained therein; use COMMIT as the version string.  When CORE is true, build
-package modules under SOURCE using CORE, an instance of Guix."
+package modules under SOURCE or if DIRECTORY under SOURCE/DIRECTORY using
+CORE, an instance of Guix."
   ;; Running the self-build script makes it easier to update the build
   ;; procedure: the self-build script of the Guix-to-be-installed contains the
   ;; right dependencies, build procedure, etc., which the Guix-in-use may not
@@ -293,19 +308,20 @@ package modules under SOURCE using CORE, an instance of 
Guix."
                #:pull-version %pull-version))
 
       ;; Build a set of modules that extend Guix using the standard method.
-      (standard-module-derivation name source core dependencies)))
+      (standard-module-derivation name source directory core dependencies)))
 
 (define* (build-channel-instance instance
                                  #:optional core (dependencies '()))
   "Return, as a monadic value, the derivation for INSTANCE, a channel
 instance.  DEPENDENCIES is a list of extensions providing Guile modules that
 INSTANCE depends on."
-  (build-from-source (symbol->string
-                      (channel-name (channel-instance-channel instance)))
-                     (channel-instance-checkout instance)
-                     #:commit (channel-instance-commit instance)
-                     #:core core
-                     #:dependencies dependencies))
+  (let ((channel (channel-instance-channel instance)))
+    (build-from-source (symbol->string (channel-name channel))
+                       (channel-instance-checkout instance)
+                       #:commit (channel-instance-commit instance)
+                       #:core core
+                       #:dependencies dependencies
+                       #:directory (channel-directory channel))))
 
 (define (resolve-dependencies instances)
   "Return a procedure that, given one of the elements of INSTANCES, returns
-- 
2.21.0

-- 
Jan Nieuwenhuizen <address@hidden> | GNU LilyPond http://lilypond.org
Freelance IT http://JoyofSource.com | Avatar® http://AvatarAcademy.com