Tmux sessions spew async_worker_eval and async_job error messages

[WorLord]

General information

System report (output of prompt_pure_system_report):

• Zsh: zsh 5.7.1 (x86_64-apple-darwin19.0) (/bin/zsh)
• Operating system: Mac OS X 10.15.7 (19H1922)
• Terminal program: iTerm.app (3.4.16)
• Tmux: no
• Git: git version 2.24.3 (Apple Git-128)
• Pure state:
  • username: ''
  • prompt: ❯
  • version: 1.20.1
• zsh-async version: 1.8.4
• PROMPT: export PROMPT=$'%F{${prompt_pure_colors[path]}}%~%f %}%(12V.%F{$prompt_pure_colors[virtualenv]}%12v%f .)%(?.%F{$prompt_pure_colors[prompt:success]}.%F{$prompt_pure_colors[prompt:error]})${prompt_pure_state[prompt]}%f '
• Colors: typeset -g -A prompt_pure_colors=( [execution_time]=yellow [git:action]=yellow [git:arrow]=cyan [git:branch]=242 [git:branch:cached]=red [git:dirty]=218 [git:stash]=cyan [host]=242 [path]=blue [prompt:continuation]=242 [prompt:error]=red [prompt:success]=magenta [suspended_jobs]=red [user]=242 [user:root]=default [virtualenv]=242 )
• TERM: export TERM=xterm-256color
• Virtualenv: export VIRTUAL_ENV_DISABLE_PROMPT=12
• Conda: export CONDA_CHANGEPS1=no
• Detected frameworks: None

I have:

• [ X ] Tested with another terminal program and can reproduce the issue:
• [ ] Followed the integration instructions for my framework

Problem description

When running or in a Tmux, I see the following messages after every command:

async_worker_eval: no such async worker: prompt_pure
async_job: no such async worker: prompt_pure

This only happens in a Tmux.

Reproduction steps

1. Use Pure prompt
2. Type "tmux"
3. Witness messages

My .zshrc:

fpath+=("$HOME"/.zsh/pure) autoload -U promptinit; promptinit prompt pure

[maxdiebold]

I'm getting these messages in multiple cases. Initially, they only appeared when entering nix-shell and tmux, but after a reboot (with no other change), they are appearing constantly and the git info is gone. So I don't think this is tmux-specific.