gnu: gsl: Disable numerically unstable test on i686.

* gnu/packages/maths.scm (gsl): Disable test.

gnu/packages/maths.scm

@@ -79,6 +79,19 @@ the standard data file.")
        (base32
         "18qf6jzz1r3mzb5qynywv4xx3z9g61hgkbpkdrhbgqh2g7jhgfc5"))))
     (build-system gnu-build-system)
+    (arguments
+     `(#:phases
+        (alist-replace
+         'configure
+         (lambda* (#:key target system outputs #:allow-other-keys #:rest args)
+           (let ((configure (assoc-ref %standard-phases 'configure)))
+             ;; disable numerically unstable test on i686, see thread at
+             ;; http://lists.gnu.org/archive/html/bug-gsl/2011-11/msg00019.html
+             (if (string=? (or target system) "i686-linux")
+                 (substitute* "ode-initval2/Makefile.in"
+                   (("TESTS = \\$\\(check_PROGRAMS\\)") "TESTS =")))
+             (apply configure args)))
+         %standard-phases)))
     (home-page "http://www.gnu.org/software/gsl/")
     (synopsis "Numerical library for C and C++")
     (description