build-systems/gnu: Allow unpacking/repacking more kind of files.

Before this change, only plain directories, tar or zip archives were supported
as the source of a package for the GNU build system; anything else would cause
the unpack phase to fail.  Origins relying on snippets would suffer from the
same problem.

This change adds the support to use files of the following extensions: .gz,
.Z, .bz2, .lz, and .xz, even when they are not tarballs.  Files of unknown
extensions are treated as uncompressed files and supported as well.

* guix/packages.scm (patch-and-repack): Only add the compressor utility to the
PATH when the file is compressed.  Bind more inputs in the mlet, and use them
for decompressing single files.  Adjust the decompression and compression
routines.
[decompression-type]: Remove nested variable.
* guix/build/utils.scm (compressor, tarball?): New procedures.  Move
%xz-parallel-args to the new 'compression helpers' section.
* tests/packages.scm: Add tests.  Add missing copyright year for Jan.
* guix/build/gnu-build-system.scm (first-subdirectory): Return #f when no
sub-directory was found.
(unpack): Support more file types, including uncompressed plain files.

1 files changed, 34 insertions, 1 deletions

diff --git a/tests/builders.scm b/tests/builders.scm
index fdcf38ded3..624547500a 100644
--- a/tests/builders.scm
+++ b/tests/builders.scm
@@ -17,10 +17,12 @@
 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
 
 
-(define-module (test-builders)
+(define-module (tests builders)
   #:use-module (guix download)
   #:use-module (guix build-system)
   #:use-module (guix build-system gnu)
+  #:use-module (guix build gnu-build-system)
+  #:use-module (guix build utils)
   #:use-module (guix store)
   #:use-module (guix utils)
   #:use-module (guix base32)
@@ -32,7 +34,9 @@
                           package-derivation package-native-search-paths))
   #:use-module (gnu packages bootstrap)
   #:use-module (ice-9 match)
+  #:use-module (ice-9 textual-ports)
   #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-11)
   #:use-module (srfi srfi-64))
 
 ;; Test the higher-level builders.
@@ -78,4 +82,33 @@
 (test-assert "gnu-build-system"
   (build-system? gnu-build-system))
 
+(define unpack (assoc-ref %standard-phases 'unpack))
+
+(define compressors '(("gzip"  . "gz")
+                      ("xz"    . "xz")
+                      ("bzip2" . "bz2")
+                      (#f      . #f)))
+
+(for-each
+ (match-lambda
+   ((comp . ext)
+
+    (unless (network-reachable?) (test-skip 1)) ;for bootstrap binaries
+    (test-equal (string-append "gnu-build-system unpack phase, "
+                               "single file (compression: "
+                               (if comp comp "None") ")")
+      "expected text"
+      (let*-values
+          (((name) "test")
+           ((compressed-name) (if ext
+                                  (string-append name "." ext)
+                                  name))
+           ((file hash) (test-file %store compressed-name "expected text")))
+        (call-with-temporary-directory
+         (lambda (dir)
+           (with-directory-excursion dir
+             (unpack #:source file)
+             (call-with-input-file name get-string-all))))))))
+ compressors)
+
 (test-end "builders")