'make test-stem' yields No rule to make target '"./src/or/tor"'

Taking Nick's shiny new 0.2.8.1-alpha test tarball, and after building it, on Debian stable I get:

$/tmp/tor-0.2.8.1-alpha$ make test-stem
make: *** No rule to make target '"./src/or/tor"', needed by 'test-stem'.  Stop.

In the Makefile I see:

test-stem: need-stem-path $(TESTING_TOR_BINARY)

where $TESTING_TOR_BINARY is

TESTING_TOR_BINARY = "$(top_builddir)/src/or/tor"

I have a src/or/tor file just fine.

I don't know make language, so hopefully this is just an easy obvious fix.