Merge pull request #2810 from Pinata-Consulting/makefile-better-out-of-tree-experience

makefile: improve  out of ORFS tree use-case

Author: maliberty

flow/Makefile

@@ -123,7 +123,7 @@ SHELL          := /usr/bin/env bash
 #   location
 # - default is current install / clone directory
 ifeq ($(origin FLOW_HOME), undefined)
-FLOW_HOME := $(shell pwd)
+FLOW_HOME := $(abspath $(dir $(firstword $(MAKEFILE_LIST))))
 endif
 export FLOW_HOME