Comment 4 for bug 518852

I'd rather not modify the libtomcrypt code too much if I can avoid it. Does this patch work for you?

diff --git a/setup.py b/setup.py
index 9346a3d..67d8c59 100644
--- a/setup.py
+++ b/setup.py
@@ -121,6 +121,9 @@ class PCTBuildExt (build_ext):

         # Tweak compiler options
         if self.compiler.compiler_type in ('unix', 'cygwin', 'mingw32'):
+ # Tell GCC to compile using the C99 standard.
+ self.__add_compiler_option("-std=c99")
+
             # Make assert() statements always work
             self.__remove_compiler_option("-DNDEBUG")