How to define Makefile dependencies between directories?

[Allen George <al...@gmail.com>]

I just started looking into why the CL portion of the build is flaky. It
seems like the "tutorial/cl/TutorialServer" and
"tutorial/cl/TutorialClient” targets _implicitly_ expect the directory
"lib/cl/externals" to exist. This directory is built by the “all” target,
but - I guess because the dependency is implicit - if you run make -jNN the
build intermittently fails because it’s being compiled in a parallel job.

Does anyone know how I can get the CL tutorial targets to depend
_explicitly_ on the CL lib target? Are there per-language lib targets? I
tried printing out all the make targets, but could not find them. Any ideas
or suggestions?

Thanks,
Allen