utils: Remove Nixpkgs helpers.

* guix/config.scm.in (%nixpkgs): Remove.
* guix/utils.scm (%nixpkgs-directory, nixpkgs-derivation,
  nixpkgs-derivation*): Remove.
* test-env.in: Export 'NIXPKGS'.
* tests/derivations.scm (%coreutils): Remove use of
  'nixpkgs-derivation'.
* tests/snix.scm (%nixpkgs-directory): New variable.
  Adjust users accordingly.

guix/config.scm.in

@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2014 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -27,7 +27,6 @@
             %guix-register-program
             %system
             %libgcrypt
-            %nixpkgs
             %nix-instantiate
             %gzip
             %bzip2
@@ -73,11 +72,6 @@
 (define %libgcrypt
   "@LIBGCRYPT@")
 
-(define %nixpkgs
-  (if (string=? "@NIXPKGS@" "")
-      #f
-      "@NIXPKGS@"))
-
 (define %nix-instantiate
   "@NIX_INSTANTIATE@")
 

guix/utils.scm

@@ -44,10 +44,6 @@
   #:export (bytevector->base16-string
             base16-string->bytevector
 
-            %nixpkgs-directory
-            nixpkgs-derivation
-            nixpkgs-derivation*
-
             compile-time-value
             fcntl-flock
             memoize
@@ -314,40 +310,6 @@ a list of command-line arguments passed to the compression program."
         (unless (every (compose zero? cdr waitpid) pids)
           (error "compressed-output-port failure" pids))))))
 
-
-;;;
-;;; Nixpkgs.
-;;;
-
-(define %nixpkgs-directory
-  (make-parameter
-   ;; Capture the build-time value of $NIXPKGS.
-   (or %nixpkgs
-       (and=> (getenv "NIXPKGS")
-              (lambda (val)
-                ;; Bail out when passed an empty string, otherwise
-                ;; `nix-instantiate' will sit there and attempt to read
-                ;; from its standard input.
-                (if (string=? val "")
-                    #f
-                    val))))))
-
-(define* (nixpkgs-derivation attribute #:optional (system (%current-system)))
-  "Return the derivation path of ATTRIBUTE in Nixpkgs."
-  (let* ((p (open-pipe* OPEN_READ (or (getenv "NIX_INSTANTIATE")
-                                      %nix-instantiate)
-                        "-A" attribute (%nixpkgs-directory)
-                        "--argstr" "system" system))
-         (l (read-line p))
-         (s (close-pipe p)))
-    (and (zero? (status:exit-val s))
-         (not (eof-object? l))
-         l)))
-
-(define-syntax-rule (nixpkgs-derivation* attribute)
-  "Evaluate the given Nixpkgs derivation at compile-time."
-  (compile-time-value (nixpkgs-derivation attribute)))
-
 
 ;;;
 ;;; Advisory file locking.

test-env.in

@@ -84,11 +84,14 @@ then
     # Place for the substituter's cache.
     XDG_CACHE_HOME="$NIX_STATE_DIR/cache-$$"
 
+    # For the (guix import snix) tests.
+    NIXPKGS="@NIXPKGS@"
+
     export NIX_IGNORE_SYMLINK_STORE NIX_STORE_DIR			\
 	NIX_LOCALSTATE_DIR NIX_LOG_DIR NIX_STATE_DIR NIX_DB_DIR		\
 	NIX_ROOT_FINDER NIX_SETUID_HELPER GUIX_BINARY_SUBSTITUTE_URL	\
         GUIX_ALLOW_UNAUTHENTICATED_SUBSTITUTES				\
-        NIX_CONF_DIR XDG_CACHE_HOME
+        NIX_CONF_DIR XDG_CACHE_HOME NIXPKGS
 
     # Launch the daemon without chroot support because is may be
     # unavailable, for instance if we're not running as root.

tests/derivations.scm

@@ -476,8 +476,7 @@
 (define %coreutils
   (false-if-exception
    (and (network-reachable?)
-        (or (package-derivation %store %bootstrap-coreutils&co)
-            (nixpkgs-derivation "coreutils")))))
+        (package-derivation %store %bootstrap-coreutils&co))))
 
 (test-skip (if %coreutils 0 1))
 

tests/snix.scm

@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2015 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -18,11 +18,13 @@
 
 (define-module (test-snix)
   #:use-module (guix import snix)
-  #:use-module ((guix utils) #:select (%nixpkgs-directory))
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-64)
   #:use-module (ice-9 match))
 
+(define %nixpkgs-directory
+  (getenv "NIXPKGS"))
+
 (define factorize-uri
   (@@ (guix import snix) factorize-uri))
 
@@ -43,14 +45,14 @@
             ("http://example.com/2.8/foo-2.8.tgz" "2.8"
              -> ("http://example.com/" version "/foo-" version ".tgz")))))
 
-(test-skip (if (and (%nixpkgs-directory)
-                    (file-exists? (string-append (%nixpkgs-directory)
+(test-skip (if (and %nixpkgs-directory
+                    (file-exists? (string-append %nixpkgs-directory
                                                  "/default.nix")))
                0
                1))
 
 (test-assert "nixpkgs->guix-package"
-  (match (nixpkgs->guix-package (%nixpkgs-directory) "guile")
+  (match (nixpkgs->guix-package %nixpkgs-directory "guile")
     (('package
        ('name "guile")
        ('version (? string?))