Disabling backend flymake-proc-legacy-flymake because (error Can’t find a suitable init function)

[takafusui]

Hi,

I know that there are some issues regarding this, for instance, #500, but adding (remove-hook 'flymake-diagnostic-functions 'flymake-proc-legacy-flymake) does not solve the problem.

When I open a python script, Flymake automatically starts, but I find the Disabling backend flymake-proc-legacy-flymake because (error Can’t find a suitable init function) warning in the *Flymake log* buffer.
If I turn on Flymake on *.el, Flymake starts to detect errors...

Could you kindly help me how can I debug this issue?
eglot requires emacs 26.1, but I am now using 26.3 on Ubuntu 20.04. Could it be an issue, but maybe not I guess?

Thank you in advance for your help!

[joaotavora]

What is your issue? Does it have anything to do with Eglot? The warning is probably correct and not problematic.

[takafusui]

Hi,

Yes, you are correct. My issue and naive guess are the followings:
When I open a python script, eglot launches correctly and Flymake starts its process (I can see Flymake[0, 0] in the mode line).
However, it does not report anything when I add an evident error.
When I open, for instance, a *.el script, hit M-x flymake-mode, and add an evident error, it reports an error with ! as usual.
My naive guess is that since flymake is called by eglot, the flymake process is crushed somehow. But of course, maybe I am wrong...

[joaotavora]

However, it does not report anything when I add an evident error.

This is the problem here, not anything else. When using Eglot, you don't need to M-x flymake-mode it's automatically done for you.

Can you start from the beginning and tell me step by step what you do? Maybe you can, like the README suggests:

1. start an Emacs -Q
2. require (require 'eglot) or maybe just type M-x package-initialize.
3. go to the python file and type M-x eglot

Does it start correctly? If so, go on and the "evident error". Does it appear?

[takafusui]

Thank you for your prompt reply.
I start emacs by executing $emacs -Q.
Then (require 'eglot) in the scratch buffer and M-x eval-buffer, but it returns eval-buffer: Cannot open load file: No such file or directory, eglot
If I execute M-x package-initialize, it does not return anything, and when M-x eglo [No match]...

[jooon]

I had a similar problem right now, but I realized it was my fault. I had reinstalled python-language-server in a new virtualenv and forgotten to add a linter, so eglot was just not receiving any errors or warnings for flymake to highlight. Editing a file in a different language showed that eglot and flymake still worked fine.

To fix it, I installed the package with the extra identifier all like this, which installs all optional plugins:

pip install python-language-server[all]

By default python-language-server package does not depend on any linter. I guess the reason is that it supports so many and they want you to choose and made them all optional.