"scons test" fails like this:

/c/mongo-c-driver/test_simple 2> /dev/null
failed to connect
scons: *** [test] Error 1
scons: building terminated because of errors.
[Exit 2]

I had to read the code to discover that that test required a mongod running on the right port,
so I did this:

mkdir .tmp && mongod --port=27017 --pidfilepath .tmp/pid --dbpath .tmp &

with which, "scons test" succeeded