Index: libgomp/testsuite/lib/libgomp.exp
===================================================================
--- libgomp/testsuite/lib/libgomp.exp	(revision 279954)
+++ libgomp/testsuite/lib/libgomp.exp	(working copy)
@@ -171,9 +171,16 @@ proc libgomp_init { args } {
     lappend ALWAYS_CFLAGS "additional_flags=-I${srcdir}/../../include"
     lappend ALWAYS_CFLAGS "additional_flags=-I${srcdir}/.."
 
-    # For build-tree testing, also consider the library paths used for builing.
+    # For build-tree testing, also consider the library paths used for building.
     # For installed testing, we assume all that to be provided in the sysroot.
     if { $blddir != "" } {
+
+	# If --with-build-sysroot= was specified, we assume it will be needed
+	# for build-tree testing.
+	if [info exists SYSROOT_CFLAGS_FOR_TARGET] {
+	    lappend ALWAYS_CFLAGS "additional_flags=--sysroot=$SYSROOT_CFLAGS_FOR_TARGET"
+	}
+	
 	# The `-fopenacc' and `-fopenmp' options imply `-pthread', and
 	# that implies `-latomic' on some hosts, so wire in libatomic
 	# build directories.
Index: libgomp/testsuite/libgomp-test-support.exp.in
===================================================================
--- libgomp/testsuite/libgomp-test-support.exp.in	(revision 279954)
+++ libgomp/testsuite/libgomp-test-support.exp.in	(working copy)
@@ -1,5 +1,3 @@
-set GCC_UNDER_TEST {@CC@}
-
 set cuda_driver_include "@CUDA_DRIVER_INCLUDE@"
 set cuda_driver_lib "@CUDA_DRIVER_LIB@"
 set hsa_runtime_lib "@HSA_RUNTIME_LIB@"
Index: Makefile.in
===================================================================
--- Makefile.in	(revision 279954)
+++ Makefile.in	(working copy)
@@ -319,6 +319,7 @@ RAW_CXX_TARGET_EXPORTS = \
 
 NORMAL_TARGET_EXPORTS = \
 	$(BASE_TARGET_EXPORTS) \
+	SYSROOT_CFLAGS_FOR_TARGET="$(SYSROOT_CFLAGS_FOR_TARGET)"; export SYSROOT_CFLAGS_FOR_TARGET; \
 	CXX="$(CXX_FOR_TARGET) $(XGCC_FLAGS_FOR_TARGET) $$TFLAGS"; export CXX;
 
 # Where to find GMP
Index: Makefile.tpl
===================================================================
--- Makefile.tpl	(revision 279954)
+++ Makefile.tpl	(working copy)
@@ -322,6 +322,7 @@ RAW_CXX_TARGET_EXPORTS = \
 
 NORMAL_TARGET_EXPORTS = \
 	$(BASE_TARGET_EXPORTS) \
+	SYSROOT_CFLAGS_FOR_TARGET="$(SYSROOT_CFLAGS_FOR_TARGET)"; export SYSROOT_CFLAGS_FOR_TARGET; \
 	CXX="$(CXX_FOR_TARGET) $(XGCC_FLAGS_FOR_TARGET) $$TFLAGS"; export CXX;
 
 # Where to find GMP