NixOS/nixpkgs — pull request #5516 by benley (2014-12-30 23:27:49+00:00)
Title: lib: Fix matchAttrs by importing builtins.length

Before:

nix-repl> :l
nix-repl> lib.matchAttrs { foo = "bar"; } { bar = "bas"; }
error: undefined variable ‘length’ at "/home/benley/nix/nixpkgs/lib/attrsets.nix":317:10

After:

nix-repl> :l
nix-repl> lib.matchAttrs { foo = "bar"; } { bar = "bas"; }
false