Re: Emacs hangs enabling debug-on-error

[Richard Stallman]

    I sent the process a TSTP and then typed step, the process appeared
    to hang.  Repeat and then typed finish, the process appeared to
    hang - at least neither step nor finish returned a gdb prompt.

That sounds like a real hang rather than a loop.
However, a real hang can only occur in a system call.
Is it in a system call?

If not, it must be looping somehow.  Please try the si
command to see if it is looping at the assembler level.

If it is a real hang in a system call, the next question is, how is it
supposed to wake up, and why does that not occur.  Did timer signals
stop happening, perhaps?