gsl: attempt to fix

ToDo: there may be more impurities than this processor-feature test.

pkgs/development/libraries/gsl/default.nix

@@ -8,6 +8,10 @@ stdenv.mkDerivation rec {
     sha256 = "18qf6jzz1r3mzb5qynywv4xx3z9g61hgkbpkdrhbgqh2g7jhgfc5";
   };
 
+  # ToDo: there might be more impurities than FMA support check
+  patches = [ ./disable-fma.patch ]; # http://lists.gnu.org/archive/html/bug-gsl/2011-11/msg00019.html
+  patchFlags = "-p0";
+
   doCheck = true;
 
   meta = {

pkgs/development/libraries/gsl/disable-fma.patch

@@ -0,0 +1,32 @@
+--- configure.ac        2011-09-22 16:13:22 +0000
++++ configure.ac        2011-11-26 23:55:24 +0000
+@@ -381,6 +381,28 @@
+ AC_SUBST(HAVE_DARWIN_IEEE_INTERFACE)
+ AC_SUBST(HAVE_DARWIN86_IEEE_INTERFACE)
+ 
++dnl check for compiler flags to disable use of FMA
++save_cflags="$CFLAGS"
++AC_CACHE_CHECK([for compiler flags to disable use of FMA], ac_cv_c_fma_flags,
++[
++if test X"$GCC" = Xyes; then
++    fma_flags='-ffp-contract=off'
++else
++    fma_flags=
++fi
++if test X"$fma_flags" != X; then
++  CFLAGS="$fma_flags $CFLAGS"
++  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[int foo;]])],[ac_cv_c_fma_flags="$fma_flags"],[ac_cv_c_fma_flags="none"])
++else
++  ac_cv_c_fma_flags="none"
++fi])
++
++if test "$ac_cv_c_fma_flags" != "none" ; then
++   CFLAGS="$ac_cv_c_fma_flags $save_cflags"
++else
++   CFLAGS="$save_cflags"
++fi
++
+ dnl Check for IEEE control flags
+ 
+ save_cflags="$CFLAGS"
+