Error with terminfo when running bash with nix run on NixOS

cdepillabout · January 28, 2020, 6:31am

I’m trying to run bash with nix run on NixOS.

I’m using a command like this:

$ nix run nixpkgs.bash

I end up with a mostly-working bash, but some things are not working, like ansi-escape sequences and keyboard arrow keys.

In my normal bash login shell, I have a bash prompt that looks like the following:

me@my-hostname /some/path $

However, when I am the shell from nix run nixpkgs.bash, the ansi escape sequences don’t look like they are quite working. Here is what it looks like:

\[\]me\[\]@\[\]my-hostname \[\]/some/path \[\]$ \[\]

Also, when I am in the shell from nix run nixpkgs.bash, pressing an arrow key produces an escape on the screen like ^[[C, ^[[B, ^[[D, or ^[[A.

I assume this is a problem with terminfo, but I can’t figure out what could be going on. In both my normal shell, and my shell under nix run, I have the two environment variables set:

TERM=xterm-256color
TERMINFO_DIRS=/home/me/.nix-profile/share/terminfo:/etc/profiles/per-user/me/share/terminfo:/nix/var/nix/profiles/default/share/terminfo:/run/current-system/sw/share/terminfo

I’ve found the following thread talking about problems with terminfo stuff, but none of the solutions seemed to do anything for me (which makes sense, since it is about zsh…):

https://github.com/NixOS/nixpkgs/issues/19785

I should add that I don’t see this problem with nix-shell -p bash (although this is somewhat expected, since nix run and nix-shell are pretty different).

Also, here is my ~/.bashrc file, although I don’t think it is particularly related:

github.com

cdepillabout/docs/blob/7ae086d74c6100e770805901d2569149487fdcf7/dot_files/dot_bashrc

#!/bin/bash

# Test for an interactive shell.  There is no need to set anything
# past this point for scp and rcp, and it's important to refrain from
# outputting anything in those cases.

# Here is another way to do this:
# [ -z "$PS1" ] && return
if [[ $- != *i* || "$TERM" == "dumb" || "$0" != *bash ]] ; then
	# Shell is non-interactive or shell is not bash.  Be done now!
    PROMPT_COMMAND=''
    return
fi

# this gets us some functions and variables needed by various programs
if [[ -e "${HOME}/docs/code/library.sh" ]] ; then
	source "${HOME}/docs/code/library.sh"
fi

# Save the current value of PATH so we can potentially restore it later.

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edit: Oh, and this is all on nixos-19.09:

system: "x86_64-linux"
host os: Linux 4.19.84, NixOS, 19.09.1300.08e503bac6d (Loris)
multi-user?: yes
sandbox: yes
version: nix-env (Nix) 2.3
channels(root): "nixos-19.09.1300.08e503bac6d"
channels(illabout): "unstable-20.03pre202088.e89b21504f3"
nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

jonringer · January 28, 2020, 7:54am

remember there’s a difference between bash and bashInteractive package.

cdepillabout · January 28, 2020, 8:41am

Ah, that makes sense Thanks!

This worked as expected:

$ nix run nixpkgs.bashInteractive

In case anyone finds this and is interested in what is going on, bash and bashInteractive are defined similarly in all-packages.nix:

https://github.com/NixOS/nixpkgs/blob/b3729ae77f5bd3f011bd8e9784b21b5824d8d91c/pkgs/top-level/all-packages.nix#L7649

https://github.com/NixOS/nixpkgs/blob/b3729ae77f5bd3f011bd8e9784b21b5824d8d91c/pkgs/top-level/all-packages.nix#L7656-L7660

If the bash derivation gets passed the interactive flag, it gets compiled with readline support:

github.com

NixOS/nixpkgs/blob/b3729ae77f5bd3f011bd8e9784b21b5824d8d91c/pkgs/shells/bash/4.4.nix#L54-L55


      
          configureFlags = [
            (if interactive then "--with-installed-readline" else "--disable-readline")