nix 2.24.10 and newer nix-shell overrides TEMP/TMP/TEMPDIR/TMPDIR

[EBADBEEF]

Running Nix-Env: Hit environment was giving the error:

error: creating directory '/tmp/nix-shell-511600-0/nix-shell-515697-0': No such file or directory

I was getting similar errors from tasks running inside of vscode (rust-analyzer, etc...).

I worked around this issue by unsetting the temp dir variables inside of my nix shell:

pkgs.mkShell { 
...
shellHook = ''
  ...
  unset TEMP TMP TEMPDIR TMPDIR
'';
}

This comes from nix change here: NixOS/nix#11713

Change is present in nix 2.24.10 and greater.

Also it seems to me that this extension (nix-env-selector) is caching the environment and the way to update it is to run the "hit" command. That wasn't clear from the documentation at all. I thought it would evaluate the shell every time and also keep nix-shell open. I think it runs 'nix-shell ... --run export' and dumps that to a file somewhere. Anyway, not really a problem.

[TheAwesome98-Real]

can reproduce. rustc puts its temporary files in $TMPDIR/rust-(random-string), causing it to fail to compile since $TMPDIR doesn't exist. i think the extension should create it (i've just been manually doing it)