Kate: ruff not installed

Help
1

I,m using Kate v25.04.3 on Debian Trixie (fully updated). Kate’s inbuilt Output tab lists the following when developing Python v3.13 scripts.

[11:00:34 Format Error] ruff is not installed, please install it to be able to format this document!

What is ruff and how do I install it ?

Stuart

2

A guess:

I can’t say why it is needed; maybe the specific code or script was using it in a different editor?

3

Claydoh,

Thank you for your usual swift reply. Kate has now been updated as per the instructions given on docs.astral.sh. If it does not(!) work then “I’ll be back”. :slightly_smiling_face:

Stuart

4

Still having problems trying to get ruff to work. This could be due to not having actually installed the thing. :flushed_face:

Before I do that, in Kate I have had a look at Tools/Configure Kate/LSP Client/Default Server Settings (tab). Scrolling down I found the following.

"python": {
            "command": ["pylsp", "--check-parent-process"],
            "url": "https://github.com/python-lsp/python-lsp-server",
            "highlightingModeRegex": "^Python$"
        },

So, I guess my questions now are:-

Do I really need ruff to be installed, given that there seems to be a python linter/formatter already in use ?

If not, how do I get Kate to stop(!) displaying “[09:25:05 Format Error] ruff is not installed, please install it to be able to format this document!” in its Output tab at the bottom of its window?

Stuart

5

No. It is optional. If you want ruff to format your code, then you can install it. This error/warning was downgraded to just an info message (in 25.08) which is less annoying.