There is an operation in my setup which makes emacs unresponsive with high CPU.

I checked the emacs process with process monitor, but it does not wait for an other process, so I guess it must be something inside emacs.

I don't want to compile my own emacs with debug symbols (why isn't there a precompiled one?). Is there some feature inside emacs which I could start before invoking the operation, which writes into a text file what emacs is doing, so I can check where it gets stuck?

Debugging a frozen Emacs gives answers that work on Unix-like systems, but Windows doesn't have a USR2 signal. Is there a Windows equivalent?

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    Does this answer your question? How to debug slow respond or halt? (Sorry, indirect link: that's itself a duplicate of emacs.stackexchange.com/questions/506/debugging-a-frozen-emacs) – Gilles 'SO- stop being evil' Jan 31 at 11:49
  • Maybe, but I'm on windows and I don't know if there is a command line tool there to send USR2 signal – Tom Jan 31 at 12:04
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    That's important information which needs to be mentioned in your question! SIGUSR2 does not exist under Windows. I don't know if Emacs recognizes some equivalent mechanism. – Gilles 'SO- stop being evil' Jan 31 at 12:17
  • I didn't mention Windows, because I thought of some internal emacs mechanism. Like couldn't the elisp interpreter write the name and params of the currently executed function into a file while running elisp when a flag is set ? It's a very simple tracing mechanism, but it could be very useful in such situations, because one could just look at the output file to see what happens when Emacs is unresponsive. – Tom Jan 31 at 15:06
  • If it is an external process being run by Emacs that you invoked (either knowingly or unknowingly), then Windows has a system process monitor and you can quit or force-quit that process. If you can break the command loop within Emacs using C-g, then you can type M-x view-lossage to see the recent commands and start backtracing/researching from there. I'm only a hobby programmer and am unsure why you think an Emacs with debugging symbols would be useful if you haven't built it from source yourself since gdb uses the sources to debug and .gdbinit gets loaded from the src directory. – lawlist Jan 31 at 20:33

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