hyper: has a '%' in the top left, and themes has bugs in v3.0.

fix it after add : unsetopt PROMPT_SP to my .zshrc file

The problem is that Hyper incorrectly reports terminal size for some short time after the tty is created. Try adding this at the very top of ~/.zshrc and then starting Hyper.

typeset LINES COLUMNS
sleep 1
typeset LINES COLUMNS

Here’s what I get:

LINES=40
COLUMNS=100
LINES=20
COLUMNS=75

My real terminal width is 75 but Hyper says 100 for a short while. If my ~/.zshrc isn’t bloated, then zsh will print the first prompt while thinking that the terminal is 100 characters wide. If prompt_cr and prompt_sp are set (this is the default), zsh will print the following sequence before every prompt.

1. Bold % on inverted background. This is controlled by PROMPT_EOL_MARK. You can put PROMPT_EOL_MARK=X in ~/.zshrc to use the plain X character instead.
2. N - M spaces, where N is the terminal width and M is the width of PROMPT_EOL_MARK (1 by default).
3. \r (carriage return).
4. Clear to the end of line (ce termcap).

If this sequence is printed when the cursor is at the very first column, it will simply clear the current line. If the cursor is not on the first column, it’ll append % to the current line and move the cursor to the beginning of the next line.

Now let’s see what happens when the terminal says it’s 100 columns wide when it’s actually only 75 columns wide. Instead of printing % followed by 74 spaces, \r and ce (which would have no effect), zsh will print % and 99 spaces. This will wrap around to the next line. The subsequent \r and ce will clear the second line but % on the first line will remain.

To see this in action, add this at the top of ~/.zshrc and start Hyper.

PROMPT'>>>'
RPROMPT='<<<'
return

Note: That pesky percent and mangled prompt.

This is not a bug in zsh. If you replace typeset LINES COLUMNS with /bin/stty size, you’ll also get wrong data. Or you can even tell Hyper to start /bin/stty size bypassing the shell. It’ll still report wrong terminal size.

I don’t know much about Hyper but does it perchance use VTE? There is a VTE bug that causes very similar issues for all terminals that use it. See https://github.com/gnunn1/tilix/issues/1777.

(Hyper doesn’t export VTE_VERSION, so probably not using VTE?)

I’ve just tested version 3.1.0-canary.1 on macOS and it works fine.

If this is indeed a VTE bug, then it makes sense that you wouldn’t see it on macOS. VTE is GNU, a part of GNOME.

I can’t reproduce this on 3.0.2 canary.

Which OS?

I can reproduce it on Linux with VTE version 5605 and Hyper 3.0.2.

Edit: I think Hyper doesn’t use VTE, so it’s an unrelated bug. I’ve also reproduced this problem on macOS with Hyper 3.0.2.

Zsh users affected by this bug can mitigate it by installing powerlevel10k theme and enabling instant prompt through p10k configure. If you still see broken prompt when starting Hyper, add sleep 1 at the end of ~/.zshrc. This won’t make zsh startup slower thanks to instant prompt.

This is not a problem with oh-my-zsh or missing symbols, so I think this issue shouldn’t have been closed.

It occurs because hyper doesn’t deal with zsh’s option to preserve partial lines correctly (PROMPT_SP, see http://zsh.sourceforge.net/Doc/Release/Options.html#Prompting), as has been mentioned before.

This wasn’t the case in 2.x, so it must’ve been some change in 3.x that causes this incorrect behavior.

Using unsetopt PROMPT_SP is a workaround but not a fix, as the option can be quite useful as mentioned by another user.

Other terminal emulators I’ve tried so far on both macOS and Arch Linux (iTerm 2, Alacritty, kitty, Xfce Terminal) don’t seem to suffer from this problem when using the same zsh settings.

add unsetopt PROMPT_SP to your last line of .zshrc will simply solve it

This is a bad idea. Consider:

❯ unsetopt prompt_sp
❯ printf 'Hello World\nGoodbye' >message.txt
❯ cat message.txt
Hello World
❯ █

Note that the output of cat message.txt is missing the second line.

It’s a really bad idea to unset PROMPT_SP in zsh.

Same issue on Hyper 3.0.2, only in the first tab of each new window. I don’t want to use unsetopt PROMPT_SP, because I really like this ZSH feature.

Can you explain why you might want to keep this?

It’s useful for being able to see if output ends with a new line whilst keeping a consistent feel / appearance to the prompt. In instances where there is no new line, the prompt will continue from the end of the previous output without a line break.

This appears to be a regression since it was fixed in v2: https://github.com/zeit/hyper/issues/2144#issuecomment-382652061.

add unsetopt PROMPT_SP to your last line of .zshrc will simply solve it

That looks like an issue with your oh-my-zsh and not with hyper. looks like your font is missing a symbol or so?

This was present after a clean install of Catalina on my Hyper as well (as Catalina changed the default shell) and I had to use @CsarGomez fix above to remove it.

Same issue on Hyper 3.0.2, only in the first tab of each new window. I don’t want to use unsetopt PROMPT_SP, because I really like this ZSH feature.

This solution fixed it for me. https://github.com/zeit/hyper/issues/2144#issuecomment-326741620