deleted file mode 100644
--- a/build/moz.configure/no-toolchain.configure
+++ /dev/null
@@ -1,20 +0,0 @@
-# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-@depends('--help')
-def no_toolchain_compiler(_):
-    return namespace(
-        wrapper=(),
-        compiler='',
-        flags=(),
-        type='',
-        version='',
-    )
-
-c_compiler = no_toolchain_compiler
-cxx_compiler = no_toolchain_compiler
-host_c_compiler = no_toolchain_compiler
-host_cxx_compiler = no_toolchain_compiler

--- a/moz.configure
+++ b/moz.configure
@@ -52,22 +52,25 @@ def compile_environment(value):
 
 set_config('COMPILE_ENVIRONMENT', compile_environment)
 add_old_configure_assignment('COMPILE_ENVIRONMENT', compile_environment)
 
 @depends('--disable-compile-environment', '--help')
 def toolchain_include(value, help):
     if value:
         return 'build/moz.configure/toolchain.configure'
-    else:
-        return 'build/moz.configure/no-toolchain.configure'
 
 include(toolchain_include)
 
-include('build/moz.configure/memory.configure')
+@depends('--disable-compile-environment', '--help')
+def memory_include(value, help):
+    if value:
+        return 'build/moz.configure/memory.configure'
+
+include(memory_include)
 
 
 @depends('--help')
 @imports(_from='mozbuild.backend', _import='backends')
 def build_backends_choices(help):
     return tuple(backends)
 
 

--- a/python/mozbuild/mozbuild/configure/__init__.py
+++ b/python/mozbuild/mozbuild/configure/__init__.py
@@ -216,20 +216,23 @@ class ConfigureSandbox(dict):
                     'Option `%s` is not handled ; reference it with a @depends'
                     % option.option
                 )
 
             self._value_for(option)
 
         # All implied options should exist.
         for implied_option in self._implied_options:
-            raise ConfigureError(
-                '`%s`, emitted from `%s` line %d, is unknown.'
-                % (implied_option.option, implied_option.caller[1],
-                   implied_option.caller[2]))
+            value = self._resolve(implied_option.value,
+                                  need_help_dependency=False)
+            if value is not None:
+                raise ConfigureError(
+                    '`%s`, emitted from `%s` line %d, is unknown.'
+                    % (implied_option.option, implied_option.caller[1],
+                       implied_option.caller[2]))
 
         # All options should have been removed (handled) by now.
         for arg in self._helper:
             without_value = arg.split('=', 1)[0]
             raise InvalidOptionError('Unknown option: %s' % without_value)
 
         # Run the execution queue
         for func, args in self._execution_queue: