+#ifdef _GL_INCLUDING_UNISTD_H
+/* Special invocation convention:
+ - On Mac OS X 10.3.9 we have a sequence of nested includes
+ <unistd.h> -> <signal.h> -> <pthread.h> -> <unistd.h>
+ In this situation, the functions are not yet declared, therefore we cannot
+ provide the C++ aliases. */
+
+#@INCLUDE_NEXT@ @NEXT_UNISTD_H@
+
+#else
+/* Normal invocation convention. */
+