nix-shell breaks if bash is in scope

[bgamari]

Issue description

Terminal handling within nix-shell appears to break if the bash derivation is in scope.

Steps to reproduce

First verify that nix-shell works if bash isn't in scope,

[ben@nixos-unstable:~]$ nix-env -e bash
uninstalling ‘bash-4.4-p12’
[ben@nixos-unstable:~]$ nix-shell '<nixpkgs>' -p rr

[nix-shell:~]$ 

Try pressing up arrow to go back in shell history, note that it works as expected. Send mouse event to TTY (e.g. click in a mouse-capable terminal emulator), note that nothing happens.

Now try bringing bash into scope,

[ben@nixos-unstable:~]$ nix-env -i bash
installing ‘bash-4.4-p12’
[ben@nixos-unstable:~]$ nix-shell '<nixpkgs>' -p rr

\[\][nix-shell:~]$\[\] 

Note how prompt is mangled, pressing up arrow key results in ^[[A being echoed to terminal instead of moving within shell history. Things are generally broken.

Technical details

• System: 18.03pre116572.9824ca6975 (Impala), also confirmed on 17.03.
• Nix version: nix-env (Nix) 1.11.15
• Nixpkgs version: "18.03pre116572.9824ca6975"
• Sandboxing enabled: build-use-sandbox = false
• nix-shell version: nix-shell (Nix) 1.11.15

[bgamari]

@cleverca22 points out on #nixos that bash lacks interactive support. I should really be using bash-interactive.

[danbst]

I observe same "picture" when run nix-shell inside nix-shell, btw

[danbst@LX:~]$ nix-shell -p stdenv

[nix-shell:~]$ nix-shell -p stdenv

\[\][nix-shell:~]$\[\] 

EDIT: oh nice, the trick from @cleverca22 fixes my issue too!

[lukateras]

This is a Nix issue.

[lukateras]

And I can't reproduce it with nixUnstable:

[chronos@yegatool:/tmp]$ nix-env -iA nixos.nixUnstable
installing ‘nix-unstable-1.12pre5732_fd10f6f2’
building path(s) ‘/nix/store/wkbfp2anpzcv6b16mr7h97vmr7nqjvs5-user-environment’
created 7 symlinks in user environment

[chronos@yegatool:/tmp]$ nix-shell --version
nix-shell (Nix) 1.12pre5732_fd10f6f2

[chronos@yegatool:/tmp]$ nix-env -i bash
installing 'bash-4.4-p12'

[chronos@yegatool:/tmp]$ nix-shell '<nixpkgs> -p rr
>

[chronos@yegatool:/tmp]$ nix-env -iA nixos.nixUnstable
installing ‘nix-unstable-1.12pre5732_fd10f6f2’
building path(s) ‘/nix/store/wkbfp2anpzcv6b16mr7h97vmr7nqjvs5-user-environment’
created 7 symlinks in user environment

[chronos@yegatool:/tmp]$ which nix-shell
/home/chronos/.nix-profile/bin/nix-shell

[chronos@yegatool:/tmp]$ nix-shell --version
nix-shell (Nix) 1.12pre5732_fd10f6f2

[chronos@yegatool:/tmp]$ nix-shell -p stdenv

[nix-shell:/tmp]$ nix-shell -p stdenv

[nix-shell:/tmp]$ nix-shell -p stdenv

[nix-shell:/tmp]$ 

[danbst]

Yeah, looks like NixOS/nix@c94f3d5 fixed it

[danbst]

Actually, this is quite a duplicate
#27126
NixOS/nix#756
NixOS/nix#730

And pending fix for 1.11.x
NixOS/nix#1483

[jcrben]

The PR pointed to above NixOS/nix#1483 says that it's a backport...

On Darwin, I still get a broken shell if I run a pure shell (arrow buttons do not work):

Passing -p bashInteractive fixes the shell, but best if it's unbroken by default:

But on my NixOS 18.03 Thinkpad, not having the same problem. nevermind, arrow keys are also broken on NixOS

[stale]

Thank you for your contributions.

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