ERL-274: dbg:p/2 bug

[OTP-Maintainer]

Original reporter: sdl.web@gmail.com
Affected version: OTP-19.0
Fixed in version: OTP-19.2
Component: erts
Migrated from: https://bugs.erlang.org/browse/ERL-274

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Eval the following in eshell:

{code:erlang}1. dbg:tracer().
2. dbg:p(all, return_to).
3. dbg:i().
4. dbg:stop_clear().{code}

Step 3 should print a few dozens of processes.

Repeat the steps above for a second time. But this time only 5ish processes are printed.

Bug reproduced in Erlang 19.1 on OSX 10.12. No issue with Erlang 18.3.1.

[OTP-Maintainer]

lukas said:

Thanks for the bug report. I've implemented a fix, just have to test it before merging it upstream.

The root problem was actually in the erlang:trace/3 bif and not in dbg.

[OTP-Maintainer]

sdl.web@gmail.com said:

Thanks. What is the plan for this fix? BTW, this bug is quite annoying. Every time I run dbg and there is no output I have to start over to make sure it is not caused by this bug.

[OTP-Maintainer]

lukas said:

It will be fixed in 19.2.

I haven't merged it upstream yet as I had forgotten about it. Will merge it when I get back to the office on Monday. Thanks for the bump!

[OTP-Maintainer]

sdl.web@gmail.com said:

Sorry to be a nuisance ;)

[OTP-Maintainer]

lukas said:

Fix merged to main for release in 19.2

[OTP-Maintainer]

sdl.web@gmail.com said:

Thank you.