Nix: Cannot uninstall package with "+" in name (e.g "gtk+")

[bjornfor]

Does nix have an issue with packages having a '+' in their name? I cannot seem to get rid of this "gtk+" package:

$ nix-env -q
gtk+-2.24.28
$ nix-env -e gtk+-2.24.28
$ nix-env -q
gtk+-2.24.28

(EDIT: Using Nix 1.11.2)

[moretea]

Could you verify this by creating a minimal reproducible package, let's say pkg-test+, and testing if has the same problem?

[bjornfor]

Yes, it's reproducible:

$ cat > nix-issue-953.nix << EOF
with (import <nixpkgs> { });
{
  package =
    stdenv.mkDerivation rec {
      name = "pkg-test+-1.0";
      buildCommand = ''
        mkdir -p "$out"
        echo "Is nix-env able to uninstall a package with a + in its name?" > "$out/file"
      '';
    };
}
EOF

$ nix-build nix-issue-953.nix 
these derivations will be built:
  /nix/store/zzaaqmb4ncxfsplyz8935a68fsr65ab9-pkg-test+-1.0.drv
building path(s) ‘/nix/store/2dvzz8952kkix8qq9wkvyngg61kk28fh-pkg-test+-1.0’
/nix/store/2dvzz8952kkix8qq9wkvyngg61kk28fh-pkg-test+-1.0

$ cat result/file 
Is nix-env able to uninstall a package with a + in its name?

$ nix-env -i ./result
installing ‘pkg-test+-1.0’
building path(s) ‘/nix/store/4xvfvi6znki2cfwm6p2351yf7hkl8m53-user-environment’
created 5092 symlinks in user environment

$ nix-env -e pkg-test+-1.0
building path(s) ‘/nix/store/71f13wwdn7z97psv2fh8fxgms4f7q9b7-user-environment’
created 5092 symlinks in user environment

$ nix-env -q | grep pkg-test
pkg-test+-1.0

$ nix-env -e pkg-test+-1.0

$ nix-env -q | grep pkg-test
pkg-test+-1.0

I find it interesting that the first nix-env -e pkg-test+-1.0 actually rebuilds the user environment. So it does _something_. But the package is still in my env (proof: cat ~/.nix-profile/file Is nix-env able to uninstall a package with a + in its name?). Doing additional nix-env -e pkg-test+-1.0 does nothing (no output, exit with success).

[bjornfor]

I thought I'd just check, builtins.parseDrvName has no trouble with the '+':

nix-repl> builtins.parseDrvName "pkg-test+-1.0"
{ name = "pkg-test+"; version = "1.0"; }

[vcunat]

A nix-env bug, apparently.

[joelmo]

nix-env -e 'gtk\+' works. I don't use all features of regex, I think globs would be enough. Regex could be enabled with a flag?

[bjornfor]

@joelmo: Thanks, that's it!

[moretea]

Ah, it's actually in the man page of nix-env as well:

 gtk\\+
           Matches the package name gtk+. The + character must be escaped
           using a backslash to prevent it from being interpreted as a
           quantifier, and the backslash must be escaped in turn with another
           backslash to ensure that the shell passes it on.

[bjornfor]

Ok, then I'm closing the issue.

[ghost]

Usability problem? Maybe there should be a warning or something?