Index: contrib/bmake/unit-tests/Makefile
===================================================================
--- contrib/bmake/unit-tests/Makefile
+++ contrib/bmake/unit-tests/Makefile
@@ -150,7 +150,13 @@
 TESTS+=		envfirst
 TESTS+=		error
 TESTS+=		# escape	# broken by reverting POSIX changes
+# Ubuntu's /bin/sh (dash) appears to remove all variables where the name
+# contains characters other than [_A-Za-z0-9]. Some tests depend on environment
+# variables containing a '-' so we have to skip those tests when using dash.
+HAVE_NON_STRICT_SHELL!=(env -i a-b=yes ${.SHELL} -c env | grep -c a-b) || echo 0
+.if ${HAVE_NON_STRICT_SHELL} != 0
 TESTS+=		export
+.endif
 TESTS+=		export-all
 TESTS+=		export-env
 TESTS+=		export-variants
@@ -160,7 +166,9 @@
 TESTS+=		impsrc
 TESTS+=		include-main
 TESTS+=		lint
+.if ${HAVE_NON_STRICT_SHELL} != 0
 TESTS+=		make-exported
+.endif
 TESTS+=		misc
 TESTS+=		moderrs
 TESTS+=		modmatch