--- a/config/makefiles/xpidl/Makefile.in
+++ b/config/makefiles/xpidl/Makefile.in
@@ -67,17 +67,18 @@ registered_xpt_files := @registered_xpt_
 xpt_files := $(registered_xpt_files) @xpt_files@
 
 @xpidl_rules@
 
 depends_files := $(foreach root,$(xpidl_modules),$(idl_deps_dir)/$(root).pp)
 
 GARBAGE += $(xpt_files) $(depends_files)
 
-xpidl:: $(xpt_files) $(chrome_manifests) $(interfaces_manifests)
+#xpidl:: $(xpt_files) $(chrome_manifests) $(interfaces_manifests)
+xpidl::
 
 $(xpt_files): $(process_py) $(call mkdir_deps,$(idl_deps_dir) $(dist_include_dir))
 
 -include $(depends_files)
 
 define xpt_deps
 $(1): $(call mkdir_deps,$(dir $(1)))
 $(1): $(addsuffix .idl,$(addprefix $(dist_idl_dir)/,$($(basename $(notdir $(1)))_deps)))

--- a/js/xpconnect/tests/moz.build
+++ b/js/xpconnect/tests/moz.build
@@ -1,16 +1,16 @@
 # -*- 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/.
 
 TEST_DIRS += [
-    'idl',
+    #'idl',
     'mochitest',
     'chrome',
     'browser',
     'components/native',
 ]
 
 XPCSHELL_TESTS_MANIFESTS += [
     'unit/xpcshell.ini',

--- a/xpcom/tests/Makefile.in
+++ b/xpcom/tests/Makefile.in
@@ -7,18 +7,20 @@ MOZ_DEBUG_SYMBOLS = 1
 
 include $(topsrcdir)/config/rules.mk
 
 ifneq (,$(SIMPLE_PROGRAMS))
 libs::
 	$(INSTALL) $(SIMPLE_PROGRAMS) $(DEPTH)/_tests/xpcshell/$(relativesrcdir)/unit
 endif
 
+ifdef COMPILE_ENVIRONMENT
 libs::
 	$(INSTALL) $(DIST)/bin/components/xpcomtest.xpt $(DEPTH)/_tests/xpcshell/$(relativesrcdir)/unit
+endif
 
 ifeq (,$(filter-out WINNT, $(HOST_OS_ARCH)))
 getnativepath = $(call normalizepath,$(1))
 else
 getnativepath = $(1)
 endif
 
 abs_srcdir = $(abspath $(srcdir))