Added checks for SIGPWR and SIGUSR1. SIGPWR is defined in linux as 30 but is not defined in Darwin. Darwin defines SIGUSR1 as 30. If SIGPWR is not defined and SIGUSR1 is then config.h now defines SIGPWR as SIGUSR1. If neither are defined, SIGPWR is defined as 30.

stepmania/configure.ac

@@ -63,6 +63,17 @@ AH_VERBATIM([VA_ZZZ_NEEDED_FUNCS],
 #endif
 ])
 
+AC_CHECK_DECLS([SIGPWR, SIGUSR1],,,[#include <signal.h>])
+AH_VERBATIM([SIGNALS],
+[#if !HAVE_DECL_SIGPWR
+#if HAVE_DECL_SIGUSR1
+#define SIGPWR SIGUSR1
+#else  //!HAVE_DECL_SIGUSR1
+#define SIGPWR 30
+#endif //HAVE_DECL_SIGUSR1
+#endif //!HAVE_DECL_SIGPWR
+])
+
 case $host in
 	*-*-darwin*)
 		AC_DEFINE(DARWIN, 1, [Use different sound drivers than linux])
@@ -70,6 +81,7 @@ case $host in
 esac
 AM_CONDITIONAL(DARWIN, test x$darwin = xtrue)
 
+
 # sdl-config puts -L/usr/lib in the library search path, which reorders things
 # in a way that breaks some configurations.
 SDL_LIBS="`echo $SDL_LIBS | sed 's_-L/usr/lib/\?[[ $]]__'`"