self: Make (guix config) generation really stateless.

Previously the %CONFIG-VARIABLES list would be generated based on what
the current (guix config) contains.  Thus, it would include
'%guix-register-program', which we recently removed, because
existing (guix config) most likely contained that variable.  Since its
value could differ from machine to machine, the build farm could be
building a different config.scm, thereby preventing people from getting
substitutes.

* guix/self.scm (%config-variables): Turn into a white list instead of
taking all the remaining variables from the current (guix config).
* build-aux/build-self.scm (%config-variables): Likewise.

2 files changed, 21 insertions, 24 deletions

diff --git a/build-aux/build-self.scm b/build-aux/build-self.scm
index 5898b6515c..4de91f7fff 100644
--- a/build-aux/build-self.scm
+++ b/build-aux/build-self.scm
@@ -63,17 +63,16 @@
     %guix-home-page-url))
 
 (define %config-variables
-  ;; (guix config) variables corresponding to Guix configuration (storedir,
-  ;; localstatedir, etc.)
-  (sort (filter pair?
-                (module-map (lambda (name var)
-                              (and (not (memq name %dependency-variables))
-                                   (not (memq name %persona-variables))
-                                   (cons name (variable-ref var))))
-                            (resolve-interface '(guix config))))
-        (lambda (name+value1 name+value2)
-          (string<? (symbol->string (car name+value1))
-                    (symbol->string (car name+value2))))))
+  ;; (guix config) variables corresponding to Guix configuration.
+  (letrec-syntax ((variables (syntax-rules ()
+                               ((_)
+                                '())
+                               ((_ variable rest ...)
+                                (cons `(variable . ,variable)
+                                      (variables rest ...))))))
+    (variables %config-directory %localstatedir %state-directory
+               %store-database-directory %store-directory
+               %storedir %sysconfdir %system)))
 
 (define* (make-config.scm #:key libgcrypt zlib gzip xz bzip2
                           (package-name "GNU Guix")
diff --git a/guix/self.scm b/guix/self.scm
index 5a10f72012..cce418df41 100644
--- a/guix/self.scm
+++ b/guix/self.scm
@@ -26,9 +26,8 @@
   #:use-module (guix discovery)
   #:use-module (guix packages)
   #:use-module (guix sets)
-  #:use-module (guix utils)
   #:use-module (guix modules)
-  #:use-module (guix build utils)
+  #:use-module ((guix build utils) #:select (find-files))
   #:use-module ((guix build compile) #:select (%lightweight-optimizations))
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-9)
@@ -666,17 +665,16 @@ assumed to be part of MODULES."
     %guix-home-page-url))
 
 (define %config-variables
-  ;; (guix config) variables corresponding to Guix configuration (storedir,
-  ;; localstatedir, etc.)
-  (sort (filter pair?
-                (module-map (lambda (name var)
-                              (and (not (memq name %dependency-variables))
-                                   (not (memq name %persona-variables))
-                                   (cons name (variable-ref var))))
-                            (resolve-interface '(guix config))))
-        (lambda (name+value1 name+value2)
-          (string<? (symbol->string (car name+value1))
-                    (symbol->string (car name+value2))))))
+  ;; (guix config) variables corresponding to Guix configuration.
+  (letrec-syntax ((variables (syntax-rules ()
+                               ((_)
+                                '())
+                               ((_ variable rest ...)
+                                (cons `(variable . ,variable)
+                                      (variables rest ...))))))
+    (variables %config-directory %localstatedir %state-directory
+               %store-database-directory %store-directory
+               %storedir %sysconfdir %system)))
 
 (define* (make-config.scm #:key libgcrypt zlib gzip xz bzip2
                           (package-name "GNU Guix")