Debug StackOverflow errors

A StackOverflowException is thrown when the execution stack overflows because it contains too many nested method calls.

For example, suppose you have an app as follows:

using System;

namespace temp
    class Program
        static void Main(string[] args)
            Main(args); // Oops, this recursion won't stop.

The Main method will continuously call itself until there is no more stack space. Once there is no more stack space, execution cannot continue and so it will throw a StackOverflowException.

> dotnet run
Stack overflow.


On .NET 5 and later, the callstack is output to the console.


This article describes how to debug a stack overflow with lldb. If you are running on Windows, we suggest debugging the app with Visual Studio or Visual Studio Code.


  1. Run the app with it configured to collect a dump on crash

    > export DOTNET_DbgEnableMiniDump=1
    > dotnet run
    Stack overflow.
    Writing minidump with heap to file /tmp/coredump.6412
    Written 58191872 bytes (14207 pages) to core file


    .NET 6 standardizes on the prefix DOTNET_ instead of COMPlus_ for environment variables that configure .NET run-time behavior. However, the COMPlus_ prefix will continue to work. If you're using a previous version of the .NET runtime, you should still use the COMPlus_ prefix for environment variables.

  2. Install the SOS extension using dotnet-sos

    dotnet-sos install
  3. Debug the dump in lldb to see the failing stack

    lldb --core /temp/coredump.6412
    (lldb) bt
        frame #261930: 0x00007f59b40900cc
        frame #261931: 0x00007f59b40900cc
        frame #261932: 0x00007f59b40900cc
        frame #261933: 0x00007f59b40900cc
        frame #261934: 0x00007f59b40900cc
        frame #261935: 0x00007f5a2d4a080f`CallDescrWorkerInternal at
        frame #261936: 0x00007f5a2d3cc4c3`MethodDescCallSite::CallTargetWorker(unsigned long const*, unsigned long*, int) at callhelpers.cpp:70
        frame #261937: 0x00007f5a2d3cc468`MethodDescCallSite::CallTargetWorker(this=<unavailable>, pArguments=0x00007ffe8222e7b0, pReturnValue=0x0000000000000000, cbReturnValue=0) at callhelpers.cpp:604
        frame #261938: 0x00007f5a2d4b6182`RunMain(MethodDesc*, short, int*, PtrArray**) [inlined] MethodDescCallSite::Call(this=<unavailable>, pArguments=<unavailable>) at callhelpers.h:468
  4. The top frame 0x00007f59b40900cc is repeated several times. Use the SOS ip2md command to figure out what method is located at the 0x00007f59b40900cc address

    (lldb) ip2md 0x00007f59b40900cc
    MethodDesc:   00007f59b413ffa8
    Method Name:          temp.Program.Main(System.String[])
    Class:                00007f59b4181d40
    MethodTable:          00007f59b4190020
    mdToken:              0000000006000001
    Module:               00007f59b413dbf8
    IsJitted:             yes
    Current CodeAddr:     00007f59b40900a0
    Version History:
      ILCodeVersion:      0000000000000000
      ReJIT ID:           0
      IL Addr:            0000000000000000
         CodeAddr:           00007f59b40900a0  (MinOptJitted)
         NativeCodeVersion:  0000000000000000
    Source file:  /temp/Program.cs @ 9
  5. Go look at the indicated method temp.Program.Main(System.String[]) and source "/temp/Program.cs @ 9" to see if you can figure out what you did wrong. If it still wasn't clear you could add logging in that area of the code.

See Also