this is what the pls proof-of-concept does so far

$ ./proof-of-concept json
Fetching   json ....................... [done]
Building   json ....................... [done]
Testing    json ....................... [FAIL]

===SORRY!===

Couldn't install json: the test step failed.

This project has failing tests, which happens sometimes
for various reasons. If you want to install it despite
the failing tests, you can re-invoke ./proof-of-concept
with the option '--skip-test'.

You'll find a log file `test-json.log` in the current
directory, with output from the failing step.

$ ./proof-of-concept --skip-test json
Installing json ....................... [done]

json installed.

$