gistfile1.txt

diff --git a/configure.ac b/configure.ac
index 6d7550b..9078aa3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -347,6 +347,10 @@ AC_CHECK_HEADERS(pty.h util.h libutil.h sys/loadavg.h sys/resource.h)
 dnl solaris specific
 AC_CHECK_HEADERS(sunmath.h)
 
+dnl OSX specific.  If this header exists, we assume that extern char **environ
+dnl isn't available and we should use _NSGetEnviron().
+AC_CHECK_HEADERS(crt_externs.h)
+
 dnl ===========================================================
 dnl Checks processor type, for processor-specific stuff
 case $host in
diff --git a/src/gauche/config.h.in b/src/gauche/config.h.in
index 60ea11f..4b442fd 100644
--- a/src/gauche/config.h.in
+++ b/src/gauche/config.h.in
@@ -92,6 +92,9 @@
 /* Define to 1 if the system has clearenv */
 #undef HAVE_CLEARENV
 
+/* Define to 1 if the system has crt_extern.h */
+#undef HAVE_CRT_EXTERNS_H
+
 /* Define if uses libcrypt */
 #undef HAVE_CRYPT
 
diff --git a/src/system.c b/src/system.c
index 50b910c..88334cb 100644
--- a/src/system.c
+++ b/src/system.c
@@ -62,9 +62,16 @@
 #include <pwd.h>
 #include <sys/times.h>
 #include <sys/wait.h>
+
+# if !defined(HAVE_CRT_EXTERNS_H)
 /* POSIX defines environ, and ISO C defines __environ.
    Modern C seems to have the latter declared in unistd.h */
 extern char **environ;
+# else  /* HAVE_CRT_EXTERNS_H */
+/* On newer OSX, we can't directly access global 'environ' variable.
+   We need to use _NSGetEnviron(), and this header defines it. */
+#include <crt_externs.h>
+# endif /* HAVE_CRT_EXTERNS_H */
 #else   /* GAUCHE_WINDOWS */
 #include <lm.h>
 #include <tlhelp32.h>
@@ -2162,6 +2169,9 @@ void Scm_SetEnv(const char *name, const char *value, int overwrite)
 ScmObj Scm_Environ(void)
 {
 #if !defined(GAUCHE_WINDOWS)
+#  if defined(HAVE_CRT_EXTERNS_H)
+    char **environ = *_NSGetEnviron(); /* OSX Hack */
+#  endif /*HAVE_CRT_EXTERNS_H*/    
     if (environ == NULL) return SCM_NIL;
     else return Scm_CStringArrayToList((const char**)environ, -1,
                                        SCM_STRING_COPYING);