How to hide a global pkgs inside a nix shell? (edit: miss match of ghcide version inside nix shell)

Help
1 
[nataneb@nixos:~/haskell-practice/discord-bot]$ whereis ghcide
ghcide: /nix/store/l7ncb0skqzy12kqy3phr3812cywzw0j0-ghc-9.0.1-with-packages/bin/ghcide /nix/store/2lkk8iw148b991mrp15as76hjkj607iq-ghcide-1.4.2.3/bin/ghcide

So i have two binaries pointing to the same command. But i just want this (/nix/store/l7ncb0skqzy12kqy3phr3812cywzw0j0-ghc-9.0.1-with-packages/bin/ghcide). How can i hide the later inside a nix shell?

2

I have xmonad installed. Because of that i have another ghc in my global conf.

3

Binaries in PATH inside the shell will usually take precedence over the binaries outside. If you want to clear the outside environment including PATH to be absolutely sure, use the --pure flag.

4

I see. So there is something wrong inside my emacs config

5

Actually the problem was on my mkShell. I was trying to use pkgs.haskell.packages.ghc901 with pkgs.haskellPackages.haskell-language-server. The fix was replace the with pkgs.haskellPackages for with pkgs.haskell.packages.ghc901

6

Does that flag exist for nix shell/nix develop? Can you set it declaratively?

7

--ignore-environment / -i, not possible to set declaratively, since derivations aren’t really concerning themselves with development environment, so handling such things there would be a layer violation, imo. mkShell is basically just a hack to create fake derivations that can act as a development environment easily.