LSP fails to start in Doom Emacs default config

[JLimperg]

Version 1.1.2 of lean4-mode has been broken for me in Doom Emacs for some time due to the following error.

Setup

I'm running Doom Emacs with the lean4-mode config from the README and the latest lsp-mode. If you can't reproduce, I'll be happy to provide more specific info.

Failure

When loading a Lean file, lean4-mode seems to start properly (no errors in Messages, no error buffers). However, LSP does not start: there's no semantic syntax highlighting, no type-checking, etc. Attempting to open the infoview results in an LSP error indicating that the LSP session does not support the plainGoal method.

Additional Info

I bisected the issue down to commit 78caecefb862f1e38daff7b7cc983651e2b726eb. Reverting this commit, like here, fixes the issue.

[lzy0505]

I can confirm both the issue and the fix.