Nixpkgs: zsh does not source set-environment when run as a non-login shell

[ToxicFrog]

Issue description

When running as a non-login shell, zsh never gets the NixOS environment definitions that would let it find most binaries. This breaks things like git (because it can't find git-receive-pack or other helper binaries), and is a problem for running commands over ssh in general when the user you're running those commands as has zsh as their shell.

Steps to reproduce

• Create a user with shell = pkgs.zsh
• From another machine, ssh user@nix echo \$PATH
• Observe that (e.g.) /run/current-system/sw/bin is not in the $PATH

Technical details

When you log in, zsh executes its system zprofile script, which is in /nix/store/...zsh-$VERSION/etc/zprofile. This script in turn enables bash emulation and then sources /etc/profile, which sources /nix/store/...-set-environment. This latter script is responsible for setting up a whole pile of environment variables, including $PATH.

However, when running a command over ssh, this file is not executed; only zshenv is. This means that when logging in from the terminal or over ssh, everything works fine, but non-interactive ssh usage (including implicit use via, e.g., git or rsync) fails because it can't find any commands.

Bash doesn't have this problem because either /etc/profile or /etc/bashrc will be loaded regardless of how it's invoked, and /etc/bashrc sources /etc/profile if it hasn't been run already.

The solution is probably for Nix environment setup to be either written to, or sourced from, /etc/zshenv, which will be unconditionally executed on all zsh invocations.

• System: 16.09.909.238c7e0 (Flounder)
• Nix version: nix-env (Nix) 1.11.4
• Nixpkgs version: "16.09.909.238c7e0"

[Mic92]

What happens if the system is build with programs.zsh.enable = true in /etc/nixos/configuration.nix?

[dtzWill]

@Mic92 this resolves the problem for me! What do you think of maybe mentioning this in the configuration.nix man-page? I used the 'Example' from environment.shells thinking that's all I needed for zsh.

Anyway it'd be good for @ToxicFrog to report if that resolves the reported problem as well :).

[ToxicFrog]

That fixes it for me as well! I thought that evaluating pkgs.zsh would implicitly "enable" zsh as well.

To the extent that there's a bug here, then, I think it's in the documentation.

[Mic92]

Yes we cannot generate "/etc/zshenv" from "pkgs.zsh", this has to be done by a module.
The default zshrc there is a file in the package itself: https://github.com/NixOS/nixpkgs/blob/master/pkgs/shells/zsh/default.nix#L36

Maybe zshenv could be added here as well, which then sources the file from system.build.setEnvironment

[rdnetto]

Just ran into the same problem. IMO, there are at least three different problems here:

• the User Management section of the manual does not document how to set the shell, or that setting programs.$SHELL.enable is a requirement for non-Bash shells to work correctly
• the logic for creating a user should assert that programs.$SHELL.enable is set, and error out if it is not
• grepping the Manual for ZSH doesn't indicate anything about the existance of programs.zsh.*. It turns out this is documented in the appendix, but there are no top-level links in the manual that would tell someone it exists - I only found it by googling for the option.

EDIT: Actually, it turns out that the need to enable the shell is documented here. So the real issue is the discoverability of the appendix and its contents.

[ghost]

Having this bug with mksh, but it's puzzling since it should be sourcing /etc/profile by default. Even tried symlinking ~/.profile to /etc/profile. It is in the list of the system's environment.shells.
Here's the relevant parts of mksh's manual:

     ~/.mkshrc          User mkshrc profile (non-privileged interactive shells); see Startup files. The location can be changed at
                        compile time (for embedded systems); AOSP Android builds use /system/etc/mkshrc.
     ~/.profile         User profile (non-privileged login shells); see Startup files near the top of this manual.
     /etc/profile       System profile (login shells); see Startup files.
     /etc/shells        Shell database.
     /etc/suid_profile  Suid profile (privileged shells); see Startup files.

   Startup files
     For the actual location of these files, see FILES.  A login shell processes the system profile first.  A privileged shell then
     processes the suid profile.  A non-privileged login shell processes the user profile next.  A non-privileged interactive shell
     checks the value of the ENV parameter after subjecting it to parameter, command, arithmetic and tilde (‘~’) substitution; if
     unset or empty, the user mkshrc profile is processed; otherwise, if a file whose name is the substitution result exists, it is
     processed; non-existence is silently ignored.  A privileged shell then drops privileges if neither was the -p option given on
     the command line nor set during execution of the startup files.

[timokau]

Just ran into this problem. Another option would be to patch zsh to look at /nix/store/..../etc/zshenv instead or something.

[d-goldin]

I've run into this too and only now found the issue.

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