Enable full backtrace for exception in process spawn (#14796)

If an exception raises in the code that prepares a forked process for `exec`, the error message of this exception is written through a pipe to the original process, which then raises an exception for the calling code (`Process.run`). The error only includes a message, no stack trace. So the only stack trace you get is that of the handler which reads the message from the pipe and raises in the original process. But that's not very relevant. We want to know the location of the original exception. This patch changes from sending just the exception message, to printing the entire backtrace (`inspect_with_backtrace`).
crystal-lang · Aug 7, 2024 · edce0a3 · edce0a3
1 parent d738ac9
commit edce0a3
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/src/crystal/system/unix/process.cr b/src/crystal/system/unix/process.cr
@@ -243,8 243,9 @@ struct Crystal::System::Process
  writer_pipe.write_bytes(Errno.value.to_i)
  rescue ex
  writer_pipe.write_byte(0)
- writer_pipe.write_bytes(ex.message.try(&.bytesize) || 0)
- writer_pipe << ex.message
  message = ex.inspect_with_backtrace
  writer_pipe.write_bytes(message.bytesize)
  writer_pipe << message
  writer_pipe.close
  ensure
  LibC._exit 127