flymake-proc Failed on Startup

[Lemonsity]

Problem Description

I opened a Haskell file and got this in my *Flymake Log* buffer: (SimpleIOCommand.hs is the file I opened)

⛔ Error [flymake-proc SimpleIOCommand.hs]: init function haskell-flymake-init for /home/lemon/Projects/Scripts/SimpleIOCommand.hs failed, cleaning up

I realized this error log because in the mode line, the Flymake minor mode always display Wait. Like the following:

Flymake:Wait[0 0 0]

Flymake Backend (On Start up):

Disabled backends: 
Running backends: flymake-proc-legacy-flymake, lsp-diagnostics--flymake-backend
Reporting backends: lsp-diagnostics--flymake-backend

Misc

Trying'flymake-diagnostic-functions, Disabling Legacy

I have seen issue with disabling flymake-proc-legacy-flymake.
I have found that if I add the line

(remove-hook 'flymake-diagnostic-functions 'flymake-proc-legacy-flymake)

into my .emacs config file, evaluation .emacs, then immediately open a Haskell file, the Wait will temporarily disappear.
However, the Wait will return immediately after any edit to the file.

If I evaluate the line, my flymake backend status becomes the following:

Disabled backends: 
Running backends: lsp-diagnostics--flymake-backend
Reporting backends: 

Other

• It seems lsp-diagnostics--flymake-backend also stops reporting after any editing
• My syntax check still works
• My C-c C-l REPL still works