Cleanup build files

Makefile

@@ -2,12 +2,12 @@ OS=$(shell uname | tr [:upper:] [:lower:])
 HOST_ENV=${OS}-$(shell uname -m)
 DEVENV=devenv$(shell pwd | sed 's/\//-/g')
 DEVENV_IMAGE=nostalgia-devenv
-ifneq ($(shell which gmake),)
+ifneq ($(shell which gmake 2> /dev/null),)
 	MAKE=gmake -s
 else
 	MAKE=make -s
 endif
-ifneq ($(shell which docker),)
+ifneq ($(shell which docker 2> /dev/null),)
 	ifeq ($(shell docker inspect --format="{{.State.Status}}" ${DEVENV} 2>&1),running)
 		ENV_RUN=docker exec -i -t --user $(shell id -u ${USER}) ${DEVENV}
 	endif