Clion 2020.2 Release canditate reformat code suuuuper slow and lag...




I'm running latest clion RC one and when ever I press CTRL+ALT+L clion begins reformating code and that task is suuuper slow. Happens on a large and small projects. In both cases it can freeze entire app for 5-20 seconds. I tend to spam that shortcut about 20x a minute and oh boy this slow down coding by a lot (habbits...) 


In any case, is it just me or its a known issue?



Please send automatically generated thread dumps if you have them in the logs folder (Help | Show Log in …) or, if there are no dumps, please capture a CPU snapshot and send it to clion-support at


I'm seeing this too - after 2020.2 update reformatting is painfully slow.


Toby Ealden do you use clang-format or builtin formatter? Please provide the materials requested in the previous comment to clion-support at


I'm using clang-format, but I was before 2020.2 and it was super snappy.

I've sent the thread dumps as requested.


Hi everyone!

The problem seems to be caused by Please comment or upvote the issue in order to get updates. See if you are not familiar with YouTrack.


@Anna Falevskaya I've updated to latest clion now up from the version originally reported above. Still having the issues - yes I know the track is still open and WIP but I remember reading somewhere that there is a way to switch back to old reformating method in clion. How can I do this? I think clang now handles it and thats "new" ? Or I'm totally wrong?


Are there any updates? I'm using PyCharm 2020.2.2 and have the same issue and it is really annoying.


Kulyk Dmitry PyCharm is a different IDE, please create an issue in PyCharm tracker and my colleagues will assist you.


Dariusz Makowski there are a builtin formatter and an alternative ClangFormat formatter - The builtin formatter is not based on clangd if you meant that.