SourceKit - Very slow indexing on Catalyst

Hi, I'm developing iPhone/iPad application. I've added support for Mac Catalyst and figured out the problem with indexing.


  • indexing works fine when target device is simulator or device
  • indexing extremely slow down (almost stops) when target device is mac

I enabled SourceKit logs to find the cause of the problem.
I found that after command below indexing slows down:

Xcode[40200:401115] SourceKit-client: [2:request:775:93.6695] [70] {
   key.platform_identifier: "",
   key.indexer.arg.destination-target-id: "macosx11.1-x86_64",
   key.indexer.arg.destination-sdk-variant: "iosmac",
   key.indexer.arg.indexer-token: 1

Does anyone have similar problem and know how to fix this?

Hi @Przemek, thanks for reporting this! However this is related to Xcode, not SourceKit-LSP, could you file a bug report at and

  • Attach full logging output
  • Attach sysdiagnose output while the issue is occurring
  • Attach if possible a project that reproduces this

Please do these via, not the swift forums.