Currently in src/mongoc/Makefile.am there are lots of checks like this:

if ENABLE_SSL
INST_H_FILES += src/mongoc/mongoc-rand.h
endif

That means that if the build machine doesn't have the required dependencies (on my Ubuntu machine, libssl-dev and libsasl2-dev), then those headers aren't included in the distribution tarball by "make dist".

It seems like it should be irrelevant whether the build machine has these dependencies. We always want to include these files in the tarball.