I know you can specify prefix through make:
$ make prefix=~ install
I've added support to use the PREFIX env var if it exists, since that is it often used in different projects.
Added support to Makefile to use PREFIX env var
Added support to the Makefile to use the PREFIX env var if it exists.
+1 - I implemented the same thing before I found this request. Hopefully it will be merged soon :(
Thanks for your contribution @gvangool and @nougad. It would be great to have a similar pull request for the ITM Gitflow fork.