[Nix-dev] Is CI of pull requests broken?

[Volth]

I noticed that many pull requests [1] have failed Travis CI tests.
The reasons of failures are often very strange, especially if the
change introduced by PR looks innocent: some "file not found" or
"build times out".

Moreover, many of the merged pull requests [2] also have failed CI. It
looks like the failed CI signal nothing to the people who do merge.
Everybody just knows that CI is broken and its success or failure
means nothing. Is it so?

1. https://github.com/NixOS/nixpkgs/pulls
2. https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aclosed