run gcext test single threaded

Author: IanButterworth

test/gcext/Makefile

@@ -59,8 +59,9 @@ $(BIN)/LocalTest.jl: $(SRCDIR)/LocalTest.jl
 	cp $< $@
 endif
 
+# the test is designed to be run single threaded (without the interactive thread)
 check: $(BIN)/gcext$(EXE) $(BIN)/LocalTest.jl $(BIN)/foreignlib$(DYLIB)
-	BINDIR=$(BIN) $(JULIA) --depwarn=error $(SRCDIR)/gcext-test.jl $<
+	BINDIR=$(BIN) $(JULIA) --depwarn=error -t1,0 $(SRCDIR)/gcext-test.jl $<
 	@echo SUCCESS
 
 clean: