See Issue #9933
Some work started in PR #5872, but I can’t understand what’s going on in there…
It fixed the problem I was having (compiling in OSX 10.10.5) if there were spaces anywhere in the absolute path of the source code. Successfully compiled and passed all rpc-tests in paths with and without spaces.
GNU Make with spaces in filenames seems to be a general issue.
I will continue to bang on this and see if I break anything else.