Bug 1257516 - Handle outputting the tail of config.log for old-configure failures from moz.configure. r=ted

build/autoconf/hooks.m4

@@ -2,19 +2,10 @@ dnl This Source Code Form is subject to the terms of the Mozilla Public
 dnl License, v. 2.0. If a copy of the MPL was not distributed with this
 dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-dnl Output the contents of config.log when configure exits with an
-dnl error code.
-define([MOZ_CONFIG_LOG_TRAP],
-[changequote(<<<, >>>)dnl
-trap '[ "$?" != 0 ] && echo "------ config.log ------" && tail -n 25 config.log' EXIT
-changequote([, ])dnl
-])
-
 dnl Wrap AC_INIT_PREPARE to add the above trap.
 define([_MOZ_AC_INIT_PREPARE], defn([AC_INIT_PREPARE]))
 define([AC_INIT_PREPARE],
 [_MOZ_AC_INIT_PREPARE($1)
-MOZ_CONFIG_LOG_TRAP
 
 test "x$prefix" = xNONE && prefix=$ac_default_prefix
 # Let make expand exec_prefix.
@@ -79,7 +70,6 @@ if test "$no_recursion" != yes; then
   if ! $PYTHON $_topsrcdir/build/subconfigure.py $1; then
       exit 1
   fi
-  MOZ_CONFIG_LOG_TRAP
 fi
 ])
 

build/moz.configure/old.configure

@@ -410,8 +410,16 @@ def old_configure(prepare_configure, extra_old_configure_args, all_options,
         if isinstance(handler, logging.FileHandler):
             handler.close()
 
+    log_size = os.path.getsize('config.log')
+
     ret = subprocess.call(cmd)
     if ret:
+        with log.queue_debug():
+            with open('config.log') as fh:
+                fh.seek(log_size)
+                for line in fh:
+                    log.debug(line.rstrip())
+            log.error('old-configure failed')
         sys.exit(ret)
 
     raw_config = {}