Arm Mbed OS support forum

Unusable MBed Studio due to Clangd error on Mac

Hi, Sorry for my English, i’m French.

I use MBed Studio since some Week Ago and i don’t have any probleme to use it.

Today i’m notify to Update MBed Studio.

When i finish the Update, i have a popup screen :
Rapport de probleme pour Clangd

Process: clangd [43147]
Path: /Library/Application Support/Mbed Studio/*/clangd
Identifier: clangd
Version: 0
Code Type: X86-64 (Native)
Parent Process: Mbed Studio Helper [41180]
Responsible: clangd [43147]
User ID: 501

I can use MBed Studio with this popup (i can’t close it because it reappear), the autocompletion work.

After some time (10 minutes), a toolbar in bottom change color to Yellow and Offline appear and i can’t do anything. I can’t open some file, i can’t open About screen.

When i close MBed Studio because i can’t do anything, i have a Javascript error

A javascript error occurrend in the main process

Uncaught Exception:
Error: kill ESRCH
at process.kill (internal/process/per_thread.js:198:13)
at (/Applications/Mbed
at App.emit (events.js:187:15)

I use MacOs High Sierra on a iMac Mi2010



I’m not sure if it related to your issue but check this topic

BR, Jan

Thanks for answer but MBed Studio is allready up to date.
All plugin are OK.

I try to update Javascript but the error is allready here.

Ok, then i can recommend only Help>>Report an issue and include the log.

BR, Jan

when i look the log file, i see many line with this error

dyld: Symbol not found: ____chkstk_darwin
Referenced from: /Library/Application Support/Mbed S []
[2020-10-24T01:51:07.674] [ERROR] MbedStudio - C/C++: tudio/mbed-studio-tools/clangd/bin/clangd (which was built for Mac OS X 10.15)
Expected in: /usr/lib/libSystem.B.dylib

My MAC have MAC OS High Sierra 10.13 and i can’t update because its too old.

The only solution is to be downgrade MBed with the older Soft

I think i have found a solution, i have download clang+llvm-9.0.0-x86_64-darwin-apple.tar and i extract this i folder /library/Application Support/Mbed Studion/mbed-studio-tools/clangd and i restart the Mac.
Since i don’t have error when i start the MBed Studio.

Maybe there is a another solution but this work for me now.

Hi Nicolas,

Thank you for reporting this issue. We believe that clangd 10.0.0 we ship with Mbed Studio should work also on the older version of macOS. We will however investigate and double-check it.

Arek - Mbed Studio team


@arekzaluski I can confirm this issue is still persisting on Mac OS 10.13.6 with the latest version of Mbed Studio 1.3.1. As suggested previously, removing clang folder from Application Support/Mbed Studio seems to be helping. Any news regarding a fix of this issue? Thank you.

Best regards,


You stated last October that the MBED team would double check the issue. I’m running OS X 10.13.6 and Mbed Studio Version 1.4.1 ( and see what appears to be the same issue. Can you please either confirm the issues exists and provide some guidance on if and when it will be addressed or state the issue can not be replicated.



Can confirm that the issue continues to persist with the 1.4.2 version of Mbed Studio. Attempted brew install llvm to build clangd 12.0.0 from source, but failed without any useful error messages.

Current fix is still to download clang+llvm from here. Newer versions are all built for MacOS 10.15.