[amake]

I use Dart/Flutter LSP (lsp-dart) in Emacs all the time very successfully. “All hell breaks loose” sounds like maybe you have a project cloned or created but not yet `flutter pub get`’d, in which case I have seen it act like practically every token is an error.

[natrys]

Okay, I think I am hitting some weirdness in Dart-mode itself. But it's to do with something unrelated in my config perhaps, because now I can't reproduce this with `emacs -Q`, and my dart-mode setup itself is only `(use-package dart-mode)`.

Basically even doing something mundane like C-n/C-p in a dart-mode buffer takes up a lot of memory (~800mb), which causes very high GC pressure and everything visibly stutters. Here is the `profiler-report` output just now:

https://paste.gnugen.ch/paste/5zED

But it's not helpful beyond pointing out that `line-move` when called from `next-line` for some reason is memory intensive.

[maydup-nem]

> gc

you could maybe try the two lines here (set the megabyte count, the third number, to your own liking): https://emacs.stackexchange.com/questions/34342/is-there-any...