Debugging using lldb

Trying to build Swift 4.2 on ubuntu 16.04 on powerpc. However the build fails at swift-build-stage1:-

  • A core dump was generated by executing the swift-build-stage1, further analyzing the core dump and back tracing in gdb, the crash is found in swift based code (AssertCommon.swift).
  • Tried setting breakpoints and debugging in gdb, however the crash occurs but the breakpoints don't get hit. Also the trace flow traverses through some libraries, making debugging bit difficult.
  • Tried debugging using lldb debugger. However the executable doesn't run after setting breakpoint inside lldb. The following error is seen:
    (lldb) process launch
    error: process launch failed: 'A' packet returned an error: 8

Any pointers on how to go about the above issue and debugging using LLDB.

This likely has to do with the ptrace_scope being tightened down on your system.

Something like the following should allow you to attach.

echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope


Thanks for the suggestion.

Im trying to debug Swift 4.2 build failures inside an Ubuntu 16.04 based Docker container. I tried the suggestions you mentioned and the ones in the attached link.
However, I am still facing the same issues as in my original post.

The attached link also mentions the following:-

If you are using Docker, you will probably need these options:
docker run --cap-add=SYS_PTRACE --security-opt seccomp=unconfined

Can you confirm that I will need to delete my current docker container and recreate another one using the above option?

Deleted the existing docker container and recreated another docker container with the following options in order to try enable debugging:-

docker run --cap-add=SYS_PTRACE --security-opt seccomp=unconfined --security-opt apparmor=unconfined -it --name swift42_debug_sarvesh ubuntu:16.04 bash

After this debugging could be done.

Thanks for the help and inputs. We can close this thread.