no need for the extra task, every shell name is already a task

Makefile

@@ -1,7 +1,7 @@
 URCHIN=`which urchin`
 SHELLS=sh bash dash ksh zsh
 
-.PHONY: $(SHELLS) test test_shell
+.PHONY: $(SHELLS) test
 
 fast: $(SHELLS)
 
@@ -12,9 +12,5 @@ $(SHELLS):
 test: fast
 	@$(URCHIN) -f test/slow 
 
-test_shell:
-	@printf '\n\033[0;34m%s\033[0m\n' "Running tests in $(SHELL)"
-	@$(SHELL) $(URCHIN) -f test/$(TEST_SUITE)
-
 default: test