There is this weird command repetition when using auto-completion.

You installed Pure using this method: https://github.com/sindresorhus/pure#oh-my-zsh Right? If not. Try doing that.
If you followed sindresorhus instructions and the issue is still present, this might be a problem with Hyper as concluded in https://github.com/sindresorhus/pure/issues/248.
You can try to set PURE_PROMPT_SYMBOL='>' or change font and see if the problem goes away.
Closing due to age/lack of updates. Feel free to re-open if this is still an issue.
I run into the same issue. Changing the prompt symbol to '>' doesn't help.
@niklaas could you open a new issue and fill out the details in the issue template?
@mafredri Thank you for your answer. I had been desperately looking for this issue to inform you that I could solve the problem. The Debian system lacked ncurses-term thus terminfo for tmux-256color was missing. After installing ncurses-term everything worked fine.
I found out by running reset in the terminal. An error mentioned that the terminfo couldn't be found.
@niklaas happy to hear, and thanks for reporting back! This would be good material for a troubleshooting section/document.
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@niklaas happy to hear, and thanks for reporting back! This would be good material for a troubleshooting section/document.