gnu: darktable: Improve package style.

* gnu/packages/photo.scm (darktable)[arguments]: Use G-expressions.
[native-inputs]: Remove labels.

gnu/packages/photo.scm

@@ -472,17 +472,20 @@ (define-public darktable
         (base32 "1b3vr6njwqfvnrx3qpbg5aqcbl1z8nxnxcgyyw0sd4a20z33jfk0"))))
     (build-system cmake-build-system)
     (arguments
-     `(#:configure-flags '("-DBINARY_PACKAGE_BUILD=On"
+     (list
+      #:configure-flags
+      #~(list "-DBINARY_PACKAGE_BUILD=On"
               "-DBUILD_TESTING=On")
       #:phases
-       (modify-phases %standard-phases
+      #~(modify-phases %standard-phases
           (add-after 'unpack 'libOpenCL-path
             (lambda* (#:key inputs #:allow-other-keys)
               ;; Statically link to libOpenCL.
               (substitute* "./src/common/dlopencl.c"
                 (("\"libOpenCL\"")
-                (string-append "\"" (assoc-ref inputs "opencl-icd-loader")
+                 (string-append "\""
-                               "/lib/libOpenCL.so\"")))))
+                                (search-input-file inputs "/lib/libOpenCL.so")
+                                "\"")))))
           (add-after 'unpack 'fix-missing-include
             (lambda _
               ;; Fix missing include needed to build tests.  See upstream
@@ -491,43 +494,41 @@ (define-public darktable
                 (("once")
                  "once\n#include \"common/image.h\""))))
           (add-before 'configure 'prepare-build-environment
-           (lambda* (#:key inputs #:allow-other-keys)
+            (lambda _
               ;; Rawspeed fails to build with GCC due to OpenMP error:
               ;; "undefined reference to `GOMP_loop_nonmonotonic_dynamic_next'"
-             (setenv "CC" "clang") (setenv "CXX" "clang++")
+              (setenv "CC" "clang")
+              (setenv "CXX" "clang++")
               ;; Darktable looks for opencl-c.h in the LLVM dir. Guix installs
               ;; it to the Clang dir. We fix this by patching CMakeLists.txt.
               (substitute* "CMakeLists.txt"
                 (("\\$\\{LLVM_INSTALL_PREFIX\\}")
-                (assoc-ref %build-inputs "clang")))))
+                 #$(this-package-native-input "clang")))))
           (add-before 'configure 'set-LDFLAGS
-           (lambda* (#:key outputs #:allow-other-keys)
+            (lambda _
               (setenv "LDFLAGS"
-                     (string-append
+                      (string-append "-Wl,-rpath=" #$output "/lib/darktable"))))
-                      "-Wl,-rpath="
-                      (assoc-ref outputs "out") "/lib/darktable"))))
           (add-after 'install 'wrap-program
-           (lambda* (#:key inputs outputs #:allow-other-keys)
+            (lambda _
-             (wrap-program (string-append (assoc-ref outputs "out")
+              (wrap-program (string-append #$output "/bin/darktable")
-                                          "/bin/darktable")
                 ;; For GtkFileChooserDialog.
                 `("GSETTINGS_SCHEMA_DIR" =
-                 (,(string-append (assoc-ref inputs "gtk+")
+                  (,(string-append #$(this-package-input "gtk+")
                                    "/share/glib-2.0/schemas")))))))))
     (native-inputs
-     `(("clang" ,clang-11)
+     (list clang-11
-       ("cmocka" ,cmocka)
+           cmocka
-       ("desktop-file-utils" ,desktop-file-utils)
+           desktop-file-utils
-       ("glib:bin" ,glib "bin")
+           `(,glib "bin")
-       ("gobject-introspection" ,gobject-introspection)
+           gobject-introspection
-       ("intltool" ,intltool)
+           intltool
-       ("llvm" ,llvm-11) ;should match the Clang version
+           llvm-11                      ;should match the Clang version
-       ("opencl-headers" ,opencl-headers)
+           opencl-headers
-       ("perl" ,perl)
+           perl
-       ("pkg-config" ,pkg-config)
+           pkg-config
-       ("po4a" ,po4a)
+           po4a
-       ("python-wrapper" ,python-wrapper)
+           python-wrapper
-       ("ruby" ,ruby)))
+           ruby))
     (inputs
      (list bash-minimal
            cairo
@@ -578,8 +579,8 @@ (define-public darktable
     (supported-systems '("x86_64-linux" "aarch64-linux" "powerpc64le-linux"))
     (properties
      '((release-monitoring-url . "https://github.com/darktable-org/darktable/releases")))
-    (license (list license:gpl3+ ;; Darktable itself.
+    (license (list license:gpl3+        ;Darktable itself
-                   license:lgpl2.1+)))) ;; Rawspeed library.
+                   license:lgpl2.1+)))) ;Rawspeed library
 
 (define-public photoflare
   (package