diff --git a/Makefile.in b/Makefile.in
index ce811dd824e..f5cc46a06b3 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -17,13 +17,16 @@ export TOPLEVEL_BUILD := 1
 
 default::
 
-ifdef COMPILE_ENVIRONMENT
 include $(topsrcdir)/$(MOZ_BUILD_APP)/build.mk
-endif
-
 
 include $(topsrcdir)/config/config.mk
 
+ifndef LIBXUL_SDK
+ifdef COMPILE_ENVIRONMENT
+BUILD_JS = 1
+endif
+endif
+
 GARBAGE_DIRS += dist _javagen _profile staticlib
 DIST_GARBAGE = config.cache config.log config.status* config-defs.h \
    config/autoconf.mk \
@@ -35,7 +38,7 @@ ifndef MOZ_PROFILE_USE
 # We need to explicitly put backend.RecursiveMakeBackend here
 # otherwise the rule in rules.mk doesn't run early enough.
 libs binaries export tools:: CLOBBER $(topsrcdir)/configure config.status backend.RecursiveMakeBackend
-ifndef LIBXUL_SDK
+ifdef BUILD_JS
 libs binaries export tools:: js-config-status
 endif
 endif
@@ -78,7 +81,7 @@ include backend.RecursiveMakeBackend.pp
 
 default:: backend.RecursiveMakeBackend
 
-ifndef LIBXUL_SDK
+ifdef BUILD_JS
 .PHONY: js-config-status
 js-config-status:
 	$(call SUBMAKE,backend.RecursiveMakeBackend,js/src,1)
@@ -92,7 +95,7 @@ install_manifest_depends = \
   backend.RecursiveMakeBackend \
   $(NULL)
 
-ifndef LIBXUL_SDK
+ifdef BUILD_JS
 install_manifest_depends += js-config-status
 endif
 
@@ -101,12 +104,12 @@ install-manifests: $(addprefix install-dist-,$(install_manifests))
 
 .PHONY: $(addprefix install-dist-,$(install_manifests))
 $(addprefix install-dist-,$(install_manifests)): install-dist-%: $(install_manifest_depends)
-	$(call py_action,process_install_manifest,$(if $(NO_REMOVE),--no-remove )$(DIST)/$* _build_manifests/install/dist_$* $(if $(LIBXUL_SDK),,js/src/_build_manifests/install/dist_$*))
+	$(call py_action,process_install_manifest,$(if $(NO_REMOVE),--no-remove )$(DIST)/$* _build_manifests/install/dist_$* $(if $(BUILD_JS),js/src/_build_manifests/install/dist_$*))
 
 .PHONY: install-tests
 install-manifests: install-tests
 install-tests: $(install_manifest_depends)
-	$(call py_action,process_install_manifest,$(if $(NO_REMOVE),--no-remove )_tests _build_manifests/install/tests $(if $(LIBXUL_SDK),,js/src/_build_manifests/install/tests))
+	$(call py_action,process_install_manifest,$(if $(NO_REMOVE),--no-remove )_tests _build_manifests/install/tests $(if $(BUILD_JS),js/src/_build_manifests/install/tests))
 
 
 # _tests should be purged during cleaning. However, we don't want it purged
@@ -142,7 +145,7 @@ include $(topsrcdir)/testing/testsuite-targets.mk
 endif
 
 default all::
-	$(call BUILDSTATUS,TIERS export $(if $(MOZ_PSEUDO_DERECURSE),compile )libs tools)
+	$(call BUILDSTATUS,TIERS export $(if $(COMPILE_ENVIRONMENT),$(if $(MOZ_PSEUDO_DERECURSE),compile ))libs tools)
 
 include $(topsrcdir)/config/rules.mk
 
@@ -247,7 +250,7 @@ scheck::
 	@relcount=`find $(DIST)/bin -name "*.so" | xargs objdump -R | grep R_386_PC32 | wc -l` && if test $$relcount -gt 0; then echo "FAILED: R_386_PC32 relocations detected in a shared library.  Did you use a system header without adding it to config/system-headers?"; exit 1; else echo "PASSED"; fi
 endif
 
-ifndef LIBXUL_SDK
+ifdef BUILD_JS
 js/src/Makefile: subsrcdir := js/src
 
 ifdef ENABLE_TESTS
diff --git a/browser/app/Makefile.in b/browser/app/Makefile.in
index 838b32a2d62..f495df5dd16 100644
--- a/browser/app/Makefile.in
+++ b/browser/app/Makefile.in
@@ -120,8 +120,10 @@ endif #}
 
 ifneq (,$(filter-out OS2 WINNT,$(OS_ARCH)))
 
+ifdef COMPILE_ENVIRONMENT
 libs:: 
 	cp -p $(MOZ_APP_NAME)$(BIN_SUFFIX) $(DIST)/bin/$(MOZ_APP_NAME)-bin$(BIN_SUFFIX)
+endif
 
 GARBAGE += $(addprefix $(FINAL_TARGET)/defaults/pref/, firefox.js)
 
diff --git a/build/unix/elfhack/Makefile.in b/build/unix/elfhack/Makefile.in
index c8ad32877f7..1421c4e8004 100644
--- a/build/unix/elfhack/Makefile.in
+++ b/build/unix/elfhack/Makefile.in
@@ -40,9 +40,10 @@ test-ctors$(DLL_SUFFIX): DT_TYPE=INIT
 
 GARBAGE += test-array$(DLL_SUFFIX) test-ctors$(DLL_SUFFIX) test-array$(DLL_SUFFIX).bak test-ctors$(DLL_SUFFIX).bak
 
+ifndef CROSS_COMPILE
+ifdef COMPILE_ENVIRONMENT
 libs:: test-array$(DLL_SUFFIX) test-ctors$(DLL_SUFFIX)
 
-ifndef CROSS_COMPILE
 dummy: dummy.$(OBJ_SUFFIX)
 	$(CC) -o $@ $^ $(LDFLAGS)
 
@@ -53,5 +54,6 @@ libs:: dummy
 
 GARBAGE += dummy
 endif
+endif
 
 test.$(OBJ_SUFFIX): CFLAGS := -O0
diff --git a/config/Makefile.in b/config/Makefile.in
index 8668fbcf942..9ff0bd2252c 100644
--- a/config/Makefile.in
+++ b/config/Makefile.in
@@ -9,10 +9,12 @@
 MOZ_LIBSTDCXX_HOST_VERSION =
 
 ifndef CROSS_COMPILE
+ifdef COMPILE_ENVIRONMENT
 ifdef USE_ELF_DYNSTR_GC
 export:: elf-dynstr-gc
 endif
 endif
+endif
 
 # IMPORTANT: Disable NSBUILDROOT for this directory only, otherwise we have
 # a recursive rule for finding nsinstall and the Perl scripts.
@@ -27,6 +29,7 @@ endif
 include $(topsrcdir)/config/config.mk
 
 ifneq (WINNT,$(HOST_OS_ARCH))
+ifdef COMPILE_ENVIRONMENT
 # Ensure nsinstall is atomically created
 nsinstall$(HOST_BIN_SUFFIX): $(HOST_PROGRAM)
 	cp $^ $@.tmp
@@ -37,6 +40,7 @@ NSINSTALL_DEST := $(DIST)/bin
 NSINSTALL_TARGET := export
 INSTALL_TARGETS += NSINSTALL
 endif
+endif
 
 HEADERS_FILES = \
 	$(DEPTH)/mozilla-config.h \
diff --git a/config/makefiles/target_libs.mk b/config/makefiles/target_binaries.mk
similarity index 100%
rename from config/makefiles/target_libs.mk
rename to config/makefiles/target_binaries.mk
diff --git a/config/recurse.mk b/config/recurse.mk
index c6f90b153f2..9b2c5fb7513 100644
--- a/config/recurse.mk
+++ b/config/recurse.mk
@@ -112,6 +112,7 @@ ifeq ($(CURRENT_TIER),export)
 $(addsuffix /$(CURRENT_TIER),$(filter-out config,$(CURRENT_DIRS))): config/$(CURRENT_TIER)
 endif
 
+ifdef COMPILE_ENVIRONMENT
 ifneq (,$(filter libs binaries,$(CURRENT_TIER)))
 # When doing a "libs" build, target_libs.mk ensures the interesting dependency data
 # is available in the "binaries" stamp. Once recursion is done, aggregate all that
@@ -139,6 +140,8 @@ endif
 
 DIST_GARBAGE += binaries-deps.mk binaries-deps
 
+endif
+
 else
 
 # Don't recurse if MAKELEVEL is NO_RECURSE_MAKELEVEL as defined above, but
@@ -209,6 +212,8 @@ endif
 endif
 endif
 
+ifdef COMPILE_ENVIRONMENT
+
 # Aggregate all dependency files relevant to a binaries build except in
 # the mozilla top-level directory.
 ifneq (_.,$(recurse_targets)_$(DEPTH))
@@ -227,4 +232,6 @@ ifneq (_.,$(recurse_targets)_$(DEPTH))
 	@$(if $(or $(recurse_targets),$^),$(call py_action,link_deps,-o binaries --group-all $(if $(want_abspaths),--abspaths )--topsrcdir $(topsrcdir) --topobjdir $(DEPTH) --dist $(DIST) $(ALL_DEP_FILES)))
 endif
 
+endif
+
 endif # ifdef MOZ_PSEUDO_DERECURSE
diff --git a/config/rules.mk b/config/rules.mk
index 3caef33c53c..3728cf28c02 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -122,6 +122,7 @@ endif
 endif
 
 ifdef CPP_UNIT_TESTS
+ifdef COMPILE_ENVIRONMENT
 
 # Compile the tests to $(DIST)/bin.  Make lots of niceties available by default
 # through TestHarness.h, by modifying the list of includes and the libs against
@@ -153,6 +154,7 @@ cppunittests-remote:
 		echo "please prepare your host with environment variables for TEST_DEVICE"; \
 	fi
 
+endif # COMPILE_ENVIRONMENT
 endif # CPP_UNIT_TESTS
 
 .PHONY: check
@@ -303,6 +305,7 @@ EXCLUDED_OBJS := $(SIMPLE_PROGRAMS:$(BIN_SUFFIX)=.$(OBJ_SUFFIX))
 SIMPLE_PROGRAMS :=
 endif
 
+ifdef COMPILE_ENVIRONMENT
 ifndef TARGETS
 TARGETS			= $(LIBRARY) $(SHARED_LIBRARY) $(PROGRAM) $(SIMPLE_PROGRAMS) $(HOST_LIBRARY) $(HOST_PROGRAM) $(HOST_SIMPLE_PROGRAMS)
 endif
@@ -328,6 +331,19 @@ ifndef HOST_OBJS
 _HOST_OBJS = $(HOST_COBJS) $(HOST_CPPOBJS) $(HOST_CMOBJS) $(HOST_CMMOBJS)
 HOST_OBJS = $(strip $(_HOST_OBJS))
 endif
+else
+LIBRARY :=
+SHARED_LIBRARY :=
+IMPORT_LIBRARY :=
+REAL_LIBRARY :=
+PROGRAM :=
+SIMPLE_PROGRAMS :=
+HOST_LIBRARY :=
+HOST_PROGRAM :=
+HOST_SIMPLE_PROGRAMS :=
+SDK_BINARY := $(filter %.py,$(SDK_BINARY))
+SDK_LIBRARY :=
+endif
 
 ALL_TRASH = \
 	$(GARBAGE) $(TARGETS) $(OBJS) $(PROGOBJS) LOGS TAGS a.out \
@@ -613,7 +629,9 @@ ifndef SUPPRESS_DEFAULT_RULES
 default all::
 	$(MAKE) export
 ifdef MOZ_PSEUDO_DERECURSE
+ifdef COMPILE_ENVIRONMENT
 	$(MAKE) compile
+endif
 endif
 	$(MAKE) libs
 	$(MAKE) tools
@@ -642,11 +660,13 @@ HOST_LIBS_DEPS = $(filter %.$(LIB_SUFFIX),$(HOST_LIBS))
 GLOBAL_DEPS += Makefile $(DEPTH)/config/autoconf.mk $(topsrcdir)/config/config.mk
 
 ##############################################
+ifdef COMPILE_ENVIRONMENT
 OBJ_TARGETS = $(OBJS) $(PROGOBJS) $(HOST_OBJS) $(HOST_PROGOBJS)
 
 compile:: $(OBJ_TARGETS)
 
-include $(topsrcdir)/config/makefiles/target_libs.mk
+include $(topsrcdir)/config/makefiles/target_binaries.mk
+endif
 
 ifdef IS_TOOL_DIR
 # One would think "tools:: libs" would work, but it turns out that combined with
diff --git a/configure.in b/configure.in
index f135c6475bb..4cb9f733dd1 100644
--- a/configure.in
+++ b/configure.in
@@ -2498,9 +2498,10 @@ esac
 if test -z "$COMPILE_ENVIRONMENT"; then
     SKIP_COMPILER_CHECKS=1
     SKIP_LIBRARY_CHECKS=1
+else
+    MOZ_COMPILER_OPTS
 fi
 
-MOZ_COMPILER_OPTS
 if test -z "$SKIP_COMPILER_CHECKS"; then
 dnl Checks for typedefs, structures, and compiler characteristics.
 dnl ========================================================
@@ -7179,7 +7180,7 @@ if test "$USE_ELF_HACK" = 1; then
     esac
 fi
 
-if test -n "$USE_ELF_HACK"; then
+if test -n "$COMPILE_ENVIRONMENT" -a -n "$USE_ELF_HACK"; then
     dnl PT_GNU_RELRO segment makes the dynamic linker set a read-only flag on
     dnl memory addresses it maps to. The result is that by the time elfhack
     dnl kicks in, it is not possible to apply relocations because of that,
@@ -7874,7 +7875,9 @@ AC_SUBST(MOZ_PIXMAN_CFLAGS)
 AC_SUBST(MOZ_PIXMAN_LIBS)
 
 # Check for headers defining standard int types.
-MOZ_CHECK_HEADERS(stdint.h inttypes.h sys/int_types.h)
+if test -n "$COMPILE_ENVIRONMENT"; then
+    MOZ_CHECK_HEADERS(stdint.h inttypes.h sys/int_types.h)
+fi
 
 if test "$MOZ_TREE_CAIRO"; then
     MOZ_CAIRO_CFLAGS='-I$(LIBXUL_DIST)/include/cairo'
@@ -8661,6 +8664,7 @@ AC_SUBST(MOZ_FOLD_LIBS)
 AC_SUBST(MOZ_ENABLE_SZIP)
 AC_SUBST(MOZ_SZIP_FLAGS)
 
+if test -n "$COMPILE_ENVIRONMENT"; then
 AC_MSG_CHECKING([for posix_fallocate])
 AC_TRY_LINK([#define _XOPEN_SOURCE 600
   #include <fcntl.h>],
@@ -8676,7 +8680,6 @@ else
 fi
 
 dnl Check for missing components
-if test "$COMPILE_ENVIRONMENT"; then
 if test "$MOZ_X11"; then
     if test "$WITHOUT_X11"; then
         AC_MSG_ERROR([--without-x specified and MOZ_X11 still defined])
diff --git a/js/src/config/makefiles/target_libs.mk b/js/src/config/makefiles/target_binaries.mk
similarity index 100%
rename from js/src/config/makefiles/target_libs.mk
rename to js/src/config/makefiles/target_binaries.mk
diff --git a/js/src/config/recurse.mk b/js/src/config/recurse.mk
index c6f90b153f2..9b2c5fb7513 100644
--- a/js/src/config/recurse.mk
+++ b/js/src/config/recurse.mk
@@ -112,6 +112,7 @@ ifeq ($(CURRENT_TIER),export)
 $(addsuffix /$(CURRENT_TIER),$(filter-out config,$(CURRENT_DIRS))): config/$(CURRENT_TIER)
 endif
 
+ifdef COMPILE_ENVIRONMENT
 ifneq (,$(filter libs binaries,$(CURRENT_TIER)))
 # When doing a "libs" build, target_libs.mk ensures the interesting dependency data
 # is available in the "binaries" stamp. Once recursion is done, aggregate all that
@@ -139,6 +140,8 @@ endif
 
 DIST_GARBAGE += binaries-deps.mk binaries-deps
 
+endif
+
 else
 
 # Don't recurse if MAKELEVEL is NO_RECURSE_MAKELEVEL as defined above, but
@@ -209,6 +212,8 @@ endif
 endif
 endif
 
+ifdef COMPILE_ENVIRONMENT
+
 # Aggregate all dependency files relevant to a binaries build except in
 # the mozilla top-level directory.
 ifneq (_.,$(recurse_targets)_$(DEPTH))
@@ -227,4 +232,6 @@ ifneq (_.,$(recurse_targets)_$(DEPTH))
 	@$(if $(or $(recurse_targets),$^),$(call py_action,link_deps,-o binaries --group-all $(if $(want_abspaths),--abspaths )--topsrcdir $(topsrcdir) --topobjdir $(DEPTH) --dist $(DIST) $(ALL_DEP_FILES)))
 endif
 
+endif
+
 endif # ifdef MOZ_PSEUDO_DERECURSE
diff --git a/js/src/config/rules.mk b/js/src/config/rules.mk
index 3caef33c53c..3728cf28c02 100644
--- a/js/src/config/rules.mk
+++ b/js/src/config/rules.mk
@@ -122,6 +122,7 @@ endif
 endif
 
 ifdef CPP_UNIT_TESTS
+ifdef COMPILE_ENVIRONMENT
 
 # Compile the tests to $(DIST)/bin.  Make lots of niceties available by default
 # through TestHarness.h, by modifying the list of includes and the libs against
@@ -153,6 +154,7 @@ cppunittests-remote:
 		echo "please prepare your host with environment variables for TEST_DEVICE"; \
 	fi
 
+endif # COMPILE_ENVIRONMENT
 endif # CPP_UNIT_TESTS
 
 .PHONY: check
@@ -303,6 +305,7 @@ EXCLUDED_OBJS := $(SIMPLE_PROGRAMS:$(BIN_SUFFIX)=.$(OBJ_SUFFIX))
 SIMPLE_PROGRAMS :=
 endif
 
+ifdef COMPILE_ENVIRONMENT
 ifndef TARGETS
 TARGETS			= $(LIBRARY) $(SHARED_LIBRARY) $(PROGRAM) $(SIMPLE_PROGRAMS) $(HOST_LIBRARY) $(HOST_PROGRAM) $(HOST_SIMPLE_PROGRAMS)
 endif
@@ -328,6 +331,19 @@ ifndef HOST_OBJS
 _HOST_OBJS = $(HOST_COBJS) $(HOST_CPPOBJS) $(HOST_CMOBJS) $(HOST_CMMOBJS)
 HOST_OBJS = $(strip $(_HOST_OBJS))
 endif
+else
+LIBRARY :=
+SHARED_LIBRARY :=
+IMPORT_LIBRARY :=
+REAL_LIBRARY :=
+PROGRAM :=
+SIMPLE_PROGRAMS :=
+HOST_LIBRARY :=
+HOST_PROGRAM :=
+HOST_SIMPLE_PROGRAMS :=
+SDK_BINARY := $(filter %.py,$(SDK_BINARY))
+SDK_LIBRARY :=
+endif
 
 ALL_TRASH = \
 	$(GARBAGE) $(TARGETS) $(OBJS) $(PROGOBJS) LOGS TAGS a.out \
@@ -613,7 +629,9 @@ ifndef SUPPRESS_DEFAULT_RULES
 default all::
 	$(MAKE) export
 ifdef MOZ_PSEUDO_DERECURSE
+ifdef COMPILE_ENVIRONMENT
 	$(MAKE) compile
+endif
 endif
 	$(MAKE) libs
 	$(MAKE) tools
@@ -642,11 +660,13 @@ HOST_LIBS_DEPS = $(filter %.$(LIB_SUFFIX),$(HOST_LIBS))
 GLOBAL_DEPS += Makefile $(DEPTH)/config/autoconf.mk $(topsrcdir)/config/config.mk
 
 ##############################################
+ifdef COMPILE_ENVIRONMENT
 OBJ_TARGETS = $(OBJS) $(PROGOBJS) $(HOST_OBJS) $(HOST_PROGOBJS)
 
 compile:: $(OBJ_TARGETS)
 
-include $(topsrcdir)/config/makefiles/target_libs.mk
+include $(topsrcdir)/config/makefiles/target_binaries.mk
+endif
 
 ifdef IS_TOOL_DIR
 # One would think "tools:: libs" would work, but it turns out that combined with
diff --git a/js/src/configure.in b/js/src/configure.in
index 1815b0764e4..43ae288d02d 100644
--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -124,6 +124,7 @@ MOZ_ARG_DISABLE_BOOL(compile-environment,
 [  --disable-compile-environment
                           Disable compiler/library checks.],
     COMPILE_ENVIRONMENT= )
+AC_SUBST(COMPILE_ENVIRONMENT)
 
 dnl Check for Perl first -- needed for win32 SDK checks
 MOZ_PATH_PROGS(PERL, $PERL perl5 perl )
@@ -2089,7 +2090,10 @@ if test "$ENABLE_YARR_JIT"; then
     AC_DEFINE(ENABLE_YARR_JIT)
 fi
 
-MOZ_COMPILER_OPTS
+if test -n "$COMPILE_ENVIRONMENT"; then
+    MOZ_COMPILER_OPTS
+fi
+
 if test -z "$SKIP_COMPILER_CHECKS"; then
 dnl Checks for typedefs, structures, and compiler characteristics.
 dnl ========================================================
diff --git a/moz.build b/moz.build
index 86d8b958cda..ac08994c508 100644
--- a/moz.build
+++ b/moz.build
@@ -29,5 +29,4 @@ if not CONFIG['LIBXUL_SDK']:
 add_tier_dir('precompile', 'xpcom/xpidl')
 
 # Bring in the configuration for the configured application.
-if CONFIG['COMPILE_ENVIRONMENT']:
-    include('/' + CONFIG['MOZ_BUILD_APP'] + '/app.mozbuild')
+include('/' + CONFIG['MOZ_BUILD_APP'] + '/app.mozbuild')
diff --git a/testing/gtest/Makefile.in b/testing/gtest/Makefile.in
index 0bef5f897fe..d6e6d5045ed 100644
--- a/testing/gtest/Makefile.in
+++ b/testing/gtest/Makefile.in
@@ -27,6 +27,7 @@ ifeq (browser,$(MOZ_BUILD_APP))
 # And non metro linking error bug 886656:
 # LNK1112: module machine type 'x64' conflicts with target machine type 'X86'
 ifneq ($(OS_ARCH),WINNT)
+ifdef COMPILE_ENVIRONMENT
 check gtest::
 	$(MAKE) -C $(DEPTH)/toolkit/library gtestxul
 ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
@@ -35,3 +36,4 @@ endif
 	$(PYTHON) $(topsrcdir)/testing/gtest/rungtests.py --xre-path=$(DIST)/bin --symbols-path=$(DIST)/crashreporter-symbols $(DIST)/bin/$(MOZ_APP_NAME)$(BIN_SUFFIX)
 endif
 endif
+endif
diff --git a/toolkit/library/Makefile.in b/toolkit/library/Makefile.in
index ccee2114f97..ee4fc27fb18 100644
--- a/toolkit/library/Makefile.in
+++ b/toolkit/library/Makefile.in
@@ -677,9 +677,9 @@ LD := $(PYTHON) $(topsrcdir)/build/link.py $(CURDIR)/linker-vsize $(LD)
 endif
 
 ifndef LINK_GTEST
+ifdef COMPILE_ENVIRONMENT
 libs:: $(FINAL_TARGET)/dependentlibs.list
-else
-libs::
+endif
 endif
 
 .PHONY: gtestxul
diff --git a/toolkit/mozapps/update/tests/Makefile.in b/toolkit/mozapps/update/tests/Makefile.in
index 6b3a4326456..df5fc516ade 100644
--- a/toolkit/mozapps/update/tests/Makefile.in
+++ b/toolkit/mozapps/update/tests/Makefile.in
@@ -44,10 +44,12 @@ service-updater-head_DEST    := $(XPCSHELLTESTROOT)/unit_service_updater
 service-updater-head_FILES   := $(XPCSHELLTESTROOT)/unit_aus_update/head_update.js
 
 ifndef MOZ_PROFILE_GENERATE
+ifdef COMPILE_ENVIRONMENT
 INSTALL_TARGETS              += xpcshell-test-helper
 xpcshell-test-helper_TARGET  := libs
 xpcshell-test-helper_DEST    := $(XPCSHELLTESTROOT)/data
 xpcshell-test-helper_FILES   := $(DIST)/bin/TestAUSHelper$(BIN_SUFFIX)
+endif
 endif # Not MOZ_PROFILE_GENERATE
 
 _CHROME_SHARED := \
diff --git a/toolkit/toolkit.mozbuild b/toolkit/toolkit.mozbuild
index ec599fc8dc9..1bfbee8e53a 100644
--- a/toolkit/toolkit.mozbuild
+++ b/toolkit/toolkit.mozbuild
@@ -6,15 +6,16 @@
 if CONFIG['LIBXUL_SDK']:
     error('toolkit.mozbuild is not compatible with --enable-libxul-sdk=')
 
-if not CONFIG['MOZ_NATIVE_NSPR']:
-    add_tier_dir('nspr', 'config/nspr')
+if CONFIG['COMPILE_ENVIRONMENT']:
+    if not CONFIG['MOZ_NATIVE_NSPR']:
+        add_tier_dir('nspr', 'config/nspr')
 
-add_tier_dir('external', 'config/external')
+    add_tier_dir('external', 'config/external')
 
-if not CONFIG['MOZ_NATIVE_NSS']:
-    add_tier_dir('nss', 'security/build')
+    if not CONFIG['MOZ_NATIVE_NSS']:
+        add_tier_dir('nss', 'security/build')
 
-include('/config/js/js.mozbuild')
+    include('/config/js/js.mozbuild')
 
 if CONFIG['MOZ_CONTENT_SANDBOX']:
     add_tier_dir('sandbox', 'security/sandbox')
diff --git a/widget/gonk/libdisplay/moz.build b/widget/gonk/libdisplay/moz.build
index 41c4d37f20a..7ce9e95c4ff 100644
--- a/widget/gonk/libdisplay/moz.build
+++ b/widget/gonk/libdisplay/moz.build
@@ -35,7 +35,7 @@ elif CONFIG['ANDROID_VERSION'] == '15':
     SOURCES += [
         'GonkDisplayICS.cpp'
     ]
-else:
+elif CONFIG['COMPILE_ENVIRONMENT']:
     error('Unsupported platform version: %s' % (CONFIG['ANDROID_VERSION']))
 
 LIBRARY_NAME = 'display'
diff --git a/xpcom/ds/moz.build b/xpcom/ds/moz.build
index 7ca875b23ea..4613ad85942 100644
--- a/xpcom/ds/moz.build
+++ b/xpcom/ds/moz.build
@@ -105,7 +105,7 @@ elif CONFIG['OS_ARCH'] == 'Darwin':
     SOURCES += [
         'TimeStamp_darwin.cpp',
     ]
-else:
+elif CONFIG['COMPILE_ENVIRONMENT']:
     error('No TimeStamp implementation on this platform.  Build will not succeed')
 
 EXTRA_COMPONENTS += [
diff --git a/xpcom/reflect/xptcall/src/md/unix/moz.build b/xpcom/reflect/xptcall/src/md/unix/moz.build
index b1855573dcc..5a67e6ac1af 100644
--- a/xpcom/reflect/xptcall/src/md/unix/moz.build
+++ b/xpcom/reflect/xptcall/src/md/unix/moz.build
@@ -155,7 +155,7 @@ if CONFIG['OS_ARCH'] == 'Linux':
                 'xptcstubs_asm_parisc_linux.s',
                 'xptcstubs_pa32.cpp',
             ]
-        else:
+        elif CONFIG['COMPILE_ENVIRONMENT']:
             error('Unknown C++ compiler, xptcall assembly will probably be incorrect.')
 
 if CONFIG['OS_ARCH'] == 'NetBSD':