gnu: Add a tzdata variant for testing purposes.

* gnu/packages/base.scm (tzdata-2017a): New variable.
* gnu/packages/glib.scm (glib)[inputs]: Remove tzdata.
[native-inputs]: Add tzdata-2017a.
[arguments]: Add tzdata-2017a to #:disallowed-references.
* gnu/packages/statistics.scm (r)[inputs]: Remove tzdata.
[native-inputs]: Add tzdata-2017a.
[arguments]: Add tzdata-2017a to #:disallowed-references.

gnu/packages/base.scm

@@ -1044,6 +1044,31 @@ (define-public tzdata
 and daylight-saving rules.")
     (license public-domain)))
 
+;;; A "fixed" version of tzdata, which is used in the test suites of
+;;; glib and R. We can update this whenever we are able to rebuild
+;;; thousands of packages (for example, in a core-updates rebuild).
+(define-public tzdata-2017a
+  (package
+    (inherit tzdata)
+    (version "2017a")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (string-append "https://www.iana.org/time-zones/repository"
+                            "/releases/tzdata" version ".tar.gz"))
+        (sha256
+         (base32
+          "1mmv4rvcs12lrvgghw4fidczvb69yv69cmzknghcvw1c196mqfnz"))))
+    (inputs `(("tzcode" ,(origin
+                          (method url-fetch)
+                          (uri (string-append
+                                "http://www.iana.org/time-zones/repository/releases/tzcode"
+                                version ".tar.gz"))
+                          (sha256
+                           (base32
+                            "1b1q7gnlsh5hjgs5065pvajd37rmbc3k9b8cgzad1vcrifswdwh2"))))))))
+
+
 (define-public libiconv
   (package
     (name "libiconv")

gnu/packages/glib.scm

@@ -157,17 +157,18 @@ (define glib
     `(("coreutils" ,coreutils)
       ("util-linux" ,util-linux)  ; for libmount
       ("libffi" ,libffi)
-      ("zlib" ,zlib)
+      ("zlib" ,zlib)))
-      ("tzdata" ,tzdata)))     ; for tests/gdatetime.c
    (native-inputs
     `(("gettext" ,gettext-minimal)
       ("dbus" ,dbus)                              ; for GDBus tests
       ("pkg-config" ,pkg-config)
       ("python" ,python-wrapper)
       ("perl" ,perl)                              ; needed by GIO tests
-      ("bash" ,bash)))
+      ("bash" ,bash)
+      ("tzdata" ,tzdata-2017a)))                  ; for tests/gdatetime.c
    (arguments
-    '(#:phases
+    `(#:disallowed-references (,tzdata-2017a)
+      #:phases
       (modify-phases %standard-phases
         (add-before 'build 'pre-build
           (lambda* (#:key inputs outputs #:allow-other-keys)

gnu/packages/statistics.scm

@@ -113,7 +113,8 @@ (define-public r
                 "0v7wpj89b0i3ad3fi1wak5c93hywmbxv8sdnixhq8l17782nidss"))))
     (build-system gnu-build-system)
     (arguments
-     `(#:make-flags
+     `(#:disallowed-references (,tzdata-2017a)
+       #:make-flags
        (list (string-append "LDFLAGS=-Wl,-rpath="
                             (assoc-ref %outputs "out")
                             "/lib/R/lib")
@@ -187,6 +188,7 @@ (define-public r
        ("pkg-config" ,pkg-config)
        ("texinfo" ,texinfo) ; for building HTML manuals
        ("which" ,which) ; for tests/Examples/base-Ex.R
+       ("tzdata" ,tzdata-2017a)
        ("xz" ,xz)))
     (inputs
      `(;; We need not only cairo here, but pango to ensure that tests for the
@@ -194,7 +196,6 @@ (define-public r
        ("pango" ,pango)
        ("coreutils" ,coreutils)
        ("curl" ,curl)
-       ("tzdata" ,tzdata)
        ("openblas" ,openblas)
        ("gfortran" ,gfortran)
        ("icu4c" ,icu4c)