https://src.fedoraproject.org/rpms/apr/blob/rawhide/f/apr-1.7.6-autoconf.patch
https://github.com/apache/apr/pull/68
--- apr-1.7.6/build/apr_common.m4.5
+++ apr-1.7.6/build/apr_common.m4
@@ -467,19 +467,11 @@
    CFLAGS="$CFLAGS -Werror"
  fi
  AC_COMPILE_IFELSE(
-  [AC_LANG_SOURCE(
-   [
-#ifndef PACKAGE_NAME
-#include "confdefs.h"
-#endif
-   ]
-   [[$1]]
-   [int main(int argc, const char *const *argv) {]
-   [[$2]]
-   [   return 0; }]
-  )], [CFLAGS=$apr_save_CFLAGS
-$3],  [CFLAGS=$apr_save_CFLAGS
-$4])
+  [AC_LANG_PROGRAM([[$1]], [[$2]])],
+  [CFLAGS=$apr_save_CFLAGS
+   $3],
+  [CFLAGS=$apr_save_CFLAGS
+   $4])
 ])
 
 dnl
--- apr-1.7.6/build/apr_network.m4.5
+++ apr-1.7.6/build/apr_network.m4
@@ -259,11 +259,12 @@
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h>
 #endif
+#include <stdio.h>
 ],[
 int tmp = gethostbyname_r((const char *) 0, (struct hostent *) 0, 
                           (char *) 0, 0, (struct hostent **) 0, &tmp);
 /* use tmp to suppress the warning */
-tmp=0;
+puts(tmp ? "non-zero" : "zero");
 ], ac_cv_gethostbyname_r_style=glibc2, ac_cv_gethostbyname_r_style=none))
 
 if test "$ac_cv_gethostbyname_r_style" = "glibc2"; then
@@ -287,11 +288,12 @@
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h>
 #endif
+#include <stdio.h>
 ],[
 int tmp = gethostbyname_r((const char *) 0, (struct hostent *) 0, 
                           (struct hostent_data *) 0);
 /* use tmp to suppress the warning */
-tmp=0;
+puts(tmp ? "non-zero" : "zero");
 ], ac_cv_gethostbyname_r_arg=hostent_data, ac_cv_gethostbyname_r_arg=char))
 
 if test "$ac_cv_gethostbyname_r_arg" = "hostent_data"; then
@@ -327,12 +329,13 @@
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h>
 #endif
+#include <stdio.h>
 ],[
 int tmp = getservbyname_r((const char *) 0, (const char *) 0,
                           (struct servent *) 0, (char *) 0, 0,
                           (struct servent **) 0);
 /* use tmp to suppress the warning */
-tmp=0;
+puts(tmp ? "non-zero" : "zero");
 ], ac_cv_getservbyname_r_style=glibc2, ac_cv_getservbyname_r_style=none)
 
 if test "$ac_cv_getservbyname_r_style" = "none"; then
@@ -354,11 +357,12 @@
     #ifdef HAVE_STDLIB_H
     #include <stdlib.h>
     #endif
+    #include <stdio.h>
     ],[
     struct servent *tmp = getservbyname_r((const char *) 0, (const char *) 0,
                                           (struct servent *) 0, (char *) 0, 0);
     /* use tmp to suppress the warning */
-    tmp=NULL;
+    puts(tmp ? "non-zero" : "zero");
     ], ac_cv_getservbyname_r_style=solaris, ac_cv_getservbyname_r_style=none)
 fi
 
@@ -381,11 +385,12 @@
     #ifdef HAVE_STDLIB_H
     #include <stdlib.h>
     #endif
+    #include <stdio.h>
     ],[
     int tmp = getservbyname_r((const char *) 0, (const char *) 0,
                               (struct servent *) 0, (struct servent_data *) 0);
     /* use tmp to suppress the warning */
-    tmp=0;
+    puts(tmp ? "non-zero" : "zero");
     ], ac_cv_getservbyname_r_style=osf1, ac_cv_getservbyname_r_style=none)
 fi
 ])
--- apr-1.7.6/build/buildcheck.sh.5
+++ apr-1.7.6/build/buildcheck.sh
@@ -15,11 +15,11 @@
   echo "buildconf: python version $py_version (ok)"
 fi
 
-# autoconf 2.59 or newer
+# autoconf 2.61 or newer
 ac_version=`${AUTOCONF:-autoconf} --version 2>/dev/null|sed -e 's/^[^0-9]*//;s/[a-z]* *$//;q'`
 if test -z "$ac_version"; then
   echo "buildconf: autoconf not found."
-  echo "           You need autoconf version 2.59 or newer installed"
+  echo "           You need autoconf version 2.61 or newer installed"
   echo "           to build APR from SVN."
   res=1
 else
--- apr-1.7.6/configure.in.5
+++ apr-1.7.6/configure.in
@@ -145,12 +145,14 @@
     APR_CROSS_COMPILING=maybe
   elif test "x$build_alias" != "x$host_alias"; then
     APR_CROSS_COMPILING=yes
+  else
+    APR_CROSS_COMPILING=no
   fi
 else
     APR_CROSS_COMPILING=no
 fi
-
 AC_SUBST(APR_CROSS_COMPILING)
+AC_MSG_NOTICE([cross-compilation detection: $APR_CROSS_COMPILING])
 
 # Libtool might need this symbol -- it must point to the location of
 # the generated libtool script (not necessarily the "top" build dir).
@@ -1876,6 +1878,7 @@
 AC_CHECK_TYPE(ssize_t, int)
 AC_C_INLINE
 AC_C_CONST
+AC_C_VARARRAYS
 AC_FUNC_SETPGRP
 
 APR_CHECK_SOCKLEN_T
@@ -1971,6 +1974,8 @@
     AC_ERROR([could not detect a 64-bit integer type])
 fi
 
+AC_MSG_NOTICE([for apr_(u)int64_t using $int64_strfn and ${int64_value}/${uint64_value}])
+
 # If present, allow the C99 macro INT64_C to override our conversion.
 #
 # HP-UX's ANSI C compiler provides this without any includes, so we
@@ -2152,7 +2157,6 @@
     aprlfs=0     
 fi
 
-AC_MSG_CHECKING([which type to use for apr_off_t])
 if test "${ac_cv_sizeof_off_t}${apr_cv_use_lfs64}" = "4yes"; then
     # LFS is go!
     off_t_fmt='#define APR_OFF_T_FMT APR_INT64_T_FMT'
@@ -2203,7 +2207,7 @@
    off_t_fmt=d
    off_t_strfn='strtoi'
 fi
-AC_MSG_RESULT($off_t_value)
+AC_MSG_NOTICE([for apr_off_t using $off_t_strfn and $off_t_value])
 
 # Regardless of whether _LARGEFILE64_SOURCE is used, on some
 # platforms _FILE_OFFSET_BITS will affect the size of ino_t and hence
@@ -2234,7 +2238,7 @@
     fi
     ;;
 esac
-AC_MSG_NOTICE([using $ino_t_value for ino_t])
+AC_MSG_NOTICE([for apr_ino_t using $ino_t_value])
 
 # Checks for endianness
 AC_C_BIGENDIAN
--- apr-1.7.6/poll/unix/poll.c.5
+++ apr-1.7.6/poll/unix/poll.c
@@ -73,7 +73,7 @@
                                    apr_interval_time_t timeout)
 {
     int i, num_to_poll;
-#ifdef HAVE_VLA
+#ifdef HAVE_C_VARARRAYS
     /* XXX: I trust that this is a segv when insufficient stack exists? */
     struct pollfd pollset[num + 1]; /* +1 since allocating 0 is undefined behaviour */
 #elif defined(HAVE_ALLOCA)
@@ -130,7 +130,7 @@
         }
     }
     
-#if !defined(HAVE_VLA) && !defined(HAVE_ALLOCA)
+#if !defined(HAVE_C_VARARRAYS) && !defined(HAVE_ALLOCA)
     if (num > SMALL_POLLSET_LIMIT) {
         free(pollset);
     }