Firejail fails with "too long environment variables"

Sadly no, I mentioned the issue on github but no help was given there. However, someone said that the issue should have been fixed when firejail got updated which I think it did. So now, since I am running nixos-unstable, the issue no longer exists. I dont recall when it got fixed, but it did when I tried it one day. So almost definitely, the problem shouldnt exist in the next release