It's extremely common for SSS implementations to contain grave weaknesses. The readme at the github there is good news because it clearly shows that the author

It's extremely common for SSS implementations to contain grave weaknesses. The readme at the github there is good news because it clearly shows that the author is aware of these problems, making it much more likely to be secure. I have not reviewed it (beyond a glance), but based on the readme I'm confident that this one has a good chance of being secure, which is a vast improvement over most. I still think in general SSS has very limited real use (except embedded into a larger cryptosystem), but if you're going to use it at least use a version that doesn't introduce vulnerabilities!