Allow setting arbitrary environment variables in profile

Note:This bug was repurposed to be more general. It would be nice for a profile to carry environment variables that are set prior to executing the command or shell. The original issue, that $SHELL is not set for non-login commands, would be covered by this solution.

• iTerm2 version: 3.0.10
• OS version: macOS Sierra
• Attach com.googlecode.iterm2.plist here (drag-drop from finder into this window)

Detailed steps to reproduce the problem:

1. Set the initial command for a profile to be different from the login shell, supply --login to the shell if necessary
2. Launch that profile
3. echo $SHELL

What happened:

The system login shell is shown. Other programs (e.g. tmux) that rely on this variable for default behaviour use the login shell instead of the profile-specified shell. I end up configuring a lot of different places to use /usr/local/bin/bash, or even worse to try to figure it out dynamically.

What should have happened:

Should be able to transparently use per-profile shells.

I saw that you wrote on another issue that the shell is responsible for setting this variable (not the terminal) so you may not agree. If I read the bash documentation it says that $SHELL will be set to the login shell if unset at startup. So bash setting it at startup appears to be a fallback behaviour, and it is valid for the calling process to set it.

Besides, it is decidedly inconvenient to not be able to set this automatically:

1. I would like to leave my default login shell set to the bare minimum, guaranteed to be present, guaranteed to be compatible with OS X core functionality.
2. I would like to have profiles that launch different, more modern shell types (different bash versions, zsh, etc)
3. I would like to have $SHELL reflect this automatically: a. removing the requirement to try to figure it out and set it myself in the various shell startup scripts b. having subsequent programs like tmux use it automatically

It seems rather silly to launch zsh and see $SHELL set to /bin/bash. There are quite a few StackExchange questions about these kind of mismatches.

You have Prefs > Profiles > General > Command set to /usr/local/bin/bash --login, which prevents $SHELL from getting set. My earlier comment was wrong; it is the job of login to set $SHELL. In older versions of iTerm2 this was a more useful thing to do because it allowed custom initial directories to work correctly, but I don't think there's any reason to do this today unless bash is not your login shell.

I guess we could set $SHELL in this case, but there are a lot of other things that login does that we still wouldn't do, so it would only give you a false sense of hope.

$SHELL is being set but it's being set to the "login shell" (/etc/passwd) as a fallback – per description in the bash manual. Removing --login doesn't change this (and I want a login shell in this case).

When I run a terminal emulator, I can emulate a different setup rather than having a single, real terminal with login. Here, there is no login and a shell and terminal setup can be chosen per-profile. In the same way that iTerm already allows specifying terminal settings (e.g. $TERM, also set by login on other systems) and the shell, it would be very convenient for $SHELL to accurately represent the chosen shell. That doesn't mean login needs to be completely emulated.

I think your best bet would be to write a script that sets up the environment correctly. People set their profile's commands to all kinds of things that aren't shells, and it certainly wouldn't make sense for $SHELL to be set to ssh, for example. I would like to make it easier to set environment variables by profile. Maybe I'll repurpose this issue for that feature, which would cover your use case as well.

Changed title: Setting $SHELL automatically → Allow setting arbitrary environment variables in profile

Milestone changed to %Review for next version