Poetry shell - Problem when erasing accented letters

[Biganon]

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• Archlinux, 5.9.3-arch1-1
• Poetry 1.1.4
• termite v15
• zsh 5.8
• No dependencies whatsoever

Issue

Hi,

I create this very simple test script:

print("Enter something: ", end="")
text = input()
print(text)

When I run it from my normal shell (zsh 5.8) I can type "ééé", and then erase those three characters, end of the story.

When I run it from inside poetry shell, I can type "ééé", and then I can erase all the way to the "g" at the end of something, including it. So I can "erode" the prompt, so it looks like "Enter somethin". If I now type something, with or without accents, it will be written right after "somethin", and it will be correctly registered and printed to me. So I can read "Enter somethinhello", hit Enter, and "hello" gets printed on the next line.

The number of prompt characters I can erase depends on the number of accented letters I've entered first. If I enter four of them, such as "éééé", I can erase one character further, until it reads "Enter somethi".

[sinoroc]

I can recreate the issue with:

• Ubuntu 18.04
• Gnome Terminal 3.28.2
• bash 4.4.20
• Poetry 1.1.4

[finswimmer]

I have no solution for you, but I'm fascinated by this problem :) Most probably it's in encoding problem. But why does this happen only in a shell created by poetry? 🤔

[sinoroc]

@finswimmer No clue either. Shells/terminals are quite tricky to tame. Did you manage to recreate the issue?

[finswimmer]

Yes, I'm able to reproduce it, if I start the script with poetry run ... or run poetry shell first. But I'm not able if I activate the venv with source .venv/bin/activate. So it has something to do how the shell is created.

[dimbleby]

this looks like a pexpect problem, maybe the same as pexpect/pexpect#689

As there, you can recreate the issue inside the shell obtained through

python -c "import pexpect; c = pexpect.spawn('/bin/bash'); c.interact(); c.close()"

[dimbleby]

cf #18