diff --git a/src/test/confidence/hello/test.sh b/src/test/confidence/hello/test.sh
index b3098d72..006a3f01 100755
--- a/src/test/confidence/hello/test.sh
+++ b/src/test/confidence/hello/test.sh
@@ -1,4 +1,5 @@
 . ../testenv.sh
-voc hello.mod -m
+# Generate mixed source and assembly code listing
+CFLAGS="-gstabs -g1 -Wa,-acdhln=hello.s" && voc hello.mod -m
 ./hello >result
 . ../testresult.sh
diff --git a/src/tools/make/vishap.make b/src/tools/make/vishap.make
index 544b6708..ac7b5b24 100644
--- a/src/tools/make/vishap.make
+++ b/src/tools/make/vishap.make
@@ -6,9 +6,14 @@
 
 
 
+# Be independent of any CFLAGS settings in the calling environment
+CFLAGS =
+
 # Gnu make has the make initial directory in CURDIR, BSD make has it in .CURDIR.
 ROOTDIR = $(CURDIR)$(.CURDIR)
 
+# Configuration.Make is created by src/tools/make/configure.c, which is run on
+# *every* build by the makefile in the enlistment root.
 include ./Configuration.Make
 
 FLAVOUR  = $(OS).$(DATAMODEL).$(COMPILER)