libvisual: configure.ac: Be more helpful in absence of autoconf-archive and/or pkg.m4

Suggested-by: Eli Schwartz <[email protected]>

Author: hartwork

libvisual/configure.ac

@@ -112,6 +112,7 @@ AC_HEADER_DIRENT
 AC_CHECK_HEADERS([fcntl.h sys/types.h stdlib.h string.h sys/time.h unistd.h sched.h sys/sched.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
+m4_pattern_forbid([^AX_CXX_COMPILE_STDCXX_11$])
 AX_CXX_COMPILE_STDCXX_11([noext], [mandatory])
 AC_C_CONST
 AC_C_INLINE
@@ -216,6 +217,7 @@ if test x$enable_threads = xyes; then
                       [have_threads=dce],[])
   fi
   if test "x$have_threads" = xnone; then
+    m4_pattern_forbid([^PKG_CHECK_MODULES$])
     PKG_CHECK_MODULES(GTHREAD2, gthread-2.0 >= 2.2.0, [have_gthread2="yes"], [have_gthread2="no"])
     if test x"$have_gthread2" = xyes; then
       have_threads=gthread2
@@ -396,6 +398,7 @@ fi
 if test  x$lv_tool_enabled = xyes -o x$examples = xyes ; then
   # Find SDL 1.x.x
   # On success, this will set and substitute SDL_CFLAGS and SDL_LIBS
+  m4_pattern_forbid([^PKG_CHECK_MODULES$])
   PKG_CHECK_MODULES([SDL], [sdl >= 1.2.0], [], [
     AC_MSG_ERROR([*** SDL 1.2.x not installed - please install first])
   ])