configure.ac: use preprocessor to detect libpqos version

No need to run the program.

diff --git a/configure.ac b/configure.ac
index 11fb9ab3c488ae1eb661ed7fa8587970464f2123..5ed0ab3fadbe894c18d6ef6419b4a2daa8b0373c 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -4428,14 +4428,14 @@ fi
 if test "x$with_libpqos" = "xyes"; then
   SAVE_CPPFLAGS="$CPPFLAGS"
   CPPFLAGS="$CPPFLAGS $with_libpqos_cppflags"
-  AC_RUN_IFELSE(
+  AC_PREPROC_IFELSE(
     [
-      AC_LANG_PROGRAM(
+      AC_LANG_SOURCE(
         [[
           #include <pqos.h>
-        ]],
-        [[
-          return !(PQOS_VERSION >= 106)
+          #if PQOS_VERSION < 106
+          #error "required PQOS version >= 1.06"
+          #endif
         ]]
       )
     ],