autoconf-2.71: declaration ordering problem: ac_fn_c_try_run () is defined, but after attempted use

[Ondrej Dubaj]

Hi,

experiencing configure problem

./configure: line 18777: ac_fn_c_try_run: command not found

It seems that CMU_HAVE_OPENSSL brings CMU_FIND_LIB_SUBDIR brings
AC_CHECK_SIZEOF(long) ... that brings the use of *check_int and that
brings the use of ac_fn_c_try_run ... but it doesn't bring the macro
defining it.

But since AC_CHECK_SIZEOF is working fine, it seems like something else confuses
it and makes that macro think that `ac_fn_c_try_run` is already defined.

IMO there's something wrong with calling AC_TRY_RUN in AC_CACHE_VAL.
Poking at NEWS:

*** Many macros no longer AC_REQUIRE as many other macros as they used to.

  This can expose several classes of latent bugs.  These are the ones
  we know about:

   - Make sure to explicitly invoke all of the macros that set result
     variables used later in the configure script, or in generated
     Makefiles.

   - Autoconf macros that use AC_REQUIRE are not safe to use in shell
     control-flow constructs that appear outside of macros defined by
     AC_DEFUN.  Use AS_IF, AS_CASE, etc. instead.  (See the
     “Prerequisite Macros” section of the manual for details.)

     The set of macros that use AC_REQUIRE internally may change from
     release to release.  The only macros that are guaranteed *not* to
     use AC_REQUIRE are the macros for acting on the results of a
     test: AC_DEFINE, AC_SUBST, AC_MSG_*, AC_CACHE_CHECK, etc.

   - AC_REQUIRE cannot be applied to macros that need to be used with
     arguments.  Instead, invoke the macro normally, with its arguments.

Can you please investigate this ?

More information can be available here:
https://bugzilla.redhat.com/show_bug.cgi?id=1943013


Thanks.

Ondrej