Check existence of required tr headers

@@ -41,7 +41,14 @@ AM_COND_IF([HAVE_DOXYGEN],
 	   [AC_CONFIG_FILES([docs/Doxyfile])])
 
 # Checks for header files.
-AC_CHECK_HEADERS([stdarg.h string.h stdlib.h stdio.h unistd.h syslog.h sys/types.h])
+AC_CHECK_HEADERS([stdarg.h string.h stdlib.h stdio.h unistd.h syslog.h \
+		  sys/types.h])
+AC_CHECK_HEADER(trbase.h, [], [
+	AC_MSG_ERROR([unable to find the trbase header])
+])
+AC_CHECK_HEADER(trio.h, [], [
+	AC_MSG_ERROR([unable to find the trio header])
+])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_HEADER_STDBOOL