Generated Makefile (by sphinx-quickstart) should use $(MAKE) instead of make
Failure happens when typing 'make latexpdf' on platform where the make command is not GNU make. For example, on OpenBSD, the result is:
make -C build/latex all-pdf
make: unknown option -- C
usage: make [-BeiknPqrSst] [-D variable] [-d flags] [-f makefile] [-I directory] [-j max_jobs] [-m directory] [-V variable] [NAME=value] [target ...] * Error code 2
-C is a GNU make option. And the latexpdf target makes explicit reference to "make" (which in my case is BSDmake). To remedy that either replace "make" with $(MAKE) which allows the user to use GNU make and the same make for the rest of the compilation, or try to generate a portable Makefile (it might be possible if you do not use a lot of so-called GNUisms in your Makefile): in this case it suffices to do (cd build/latex/; $(MAKE) all-pdf).
Note: I have just seen the generated Makefile to build the pdf. There are a lot of GNU Makefile constructs in there. I guess the first solution (use of $(MAKE)) might be the best.