runtime: Can't attach to ASP.NET Core application when hostingModel is "InProcess" and .NET CLR version was selected

The attach to w3wp.exe which contains .NET Core v3.0.100-rc1 inside (ASP.NET Core v3 application where web.config has hostingModel="InProcess" ) hangs till the timeout when the IIS application pool configured in the following way: . The server diagnostic thread in w3wp.exe is waiting for incoming connection in ConnectNamedPipe:

  35  Id: 492c.3dd8 Suspend: 1 Teb: 000000b2`c3498000 Unfrozen
 # Child-SP          RetAddr           Call Site
00 000000b2`c467f6c8 00007ff8`91965b99 ntdll!NtFsControlFile+0x14
01 000000b2`c467f6d0 00007ff8`49ac225b KERNELBASE!ConnectNamedPipe+0x79
02 000000b2`c467f740 00007ff8`49ad39a4 coreclr!IpcStream::DiagnosticsIpc::Accept+0x7b [f:\workspace.2\_work\1\s\src\debug\debug-pal\win\diagnosticsipc.cpp @ 64] 
03 000000b2`c467f7a0 00007ff8`953c4034 coreclr!DiagnosticsServerThread+0xa4 [f:\workspace.2\_work\1\s\src\vm\diagnosticserver.cpp @ 51] 
04 000000b2`c467f850 00007ff8`955b3691 KERNEL32!BaseThreadInitThunk+0x14
05 000000b2`c467f880 00000000`00000000 ntdll!RtlUserThreadStart+0x21

It looks like the server pipe has wrong access rights in this case. It’s the reason of timeout in the client application.

The attach works properly when the .NET CLR version set to “No Managed Code”:

The detail repro case is here https://youtrack.jetbrains.com/issue/PROF-903.