poetry shell modifies $TERM env variable within tmux

• Poetry version: Poetry (version 1.4.2)
• Python version: 3.11.3
• OS version and name: macOS 13.3.1

• I am on the latest stable Poetry version, installed using a recommended method.
• I have searched the issues of this repo and believe that this is not a duplicate.
• I have consulted the FAQ and blog for any relevant entries or release notes.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option) and have included the output below.

Issue

Hey, I'm an avid tmux user and love poetry so far, thanks for your work!

The issue I am experiencing is that when I run poetry shell my $TERM env variable is being changed from screen-256color to tmux-256color which breaks my terminal colors. Manually setting it back to screen-256color works fine. I'm running zsh 5.9 as my shell of choice.

EDIT:

I can see that emulate bash -c '. .../.venv/bin/activate' is being run in my shell when I run poetry shell. The command should be POSIX-compatible so I don't see a reason for it to be emulated. Maybe that causes some kind of issues but that's just speculation on my part.

Reproduce poetry shell inside tmux using zsh 5.9 and compare $TERM before and after activation. Start at the poetry shell entry point and inspect how .venv/bin/activate is invoked, including the reported emulate bash -c command. Done means activation no longer changes $TERM from screen-256color to tmux-256color and the behavior is covered by a regression test.