1933057 - Pass `--use-local-debuginfo` to minidump-stackwalk in mozcrash.py to use local symbols already present in binaries without requiring users to invoke `mach buildsymbols` after every build

Status: RESOLVED FIXED

(Toolkit :: Crash Reporting, enhancement)

Description

[Andrew Sutherland [:asuth] (he/him)]

In this message in the crashreporting channel of chat.mozilla.org :gsvelto said:

Well, we could just pass --use-local-debuginfo to minidump-stackwalk and it should work out of the box
It should be just a matter of tweaking mozcrash.py. I'll give it a spin tomorrow.

Having looked at this a bit, it appears that this would obsolete the need for developers to manually run mach buildsymbols after every mach build if they want crashes in local test runs symbolicated. (Noting that until bug 1924260 is fixed, it's also necessary to manually pass --symbols-path to mach wpt to symbolicate successfully at all for wpt tests run locally.)

Comment 1

[Gabriele Svelto [:gsvelto]]

I finally figured why we haven't done this yet: I forgot to update the stackwalker we use in automation, so that needs to happen first.

Comment 2

[Andrew Sutherland [:asuth] (he/him)]

Attachment: mozcrash-use-local.diff

(In reply to Gabriele Svelto [:gsvelto] from comment #1)

I finally figured why we haven't done this yet: I forgot to update the stackwalker we use in automation, so that needs to happen first.

I'm confused by whether https://bugzilla.mozilla.org/show_bug.cgi?id=1933629#c5 means there's still more to do or if that dependency is solved, but if there's more to do there, on the patch attached here I keyed use of the flag on the heuristic that decides we're on a local machine and that works on my local machine (but of course I have no clue what it might do to the automation).

Comment 3

[Gabriele Svelto [:gsvelto]]

The dependency is solved but since there's more to do for that bug we're leaving it open. I'm removing the dependency since this can go forward now.

Comment 4

[Simon Chopin [:schopin]]

I'm wondering if we even need to make this conditional? AFAICT minidump-stackwalk gracefully handles missing local files.

Comment 5

[Simon Chopin [:schopin]]

Attachment: Bug 1933057 - mozcrash: use symbols in binaries for local builds r=gsvelto

If the data is already available locally, we might as well use it, as
the .sym files might not have all data, e.g. system libraries, or not be
there at all if the user hasn't run ./mach buildsymbols.

Comment 6

[Simon Chopin [:schopin]]

Attachment: Bug 1933057 - mozcrash: print both stackwalk stdout and stderr r=gsvelto

minidump-stackwalk might print spurious warnings or errors that aren't
fatal, it shouldn't suppress the entire output of mozcrash. In
particular, the next patch will have it emit warning when crashes involve
system libraries that don't have symbols.

Comment 7

[Gabriele Svelto [:gsvelto]]

Once you land this please send an e-mail to dev-platform to describe the change since it's going to be useful to pretty much anybody doing native development.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/6e195b7fe78f
https://hg.mozilla.org/integration/autoland/rev/30f93cd82865
mozcrash: print both stackwalk stdout and stderr r=gsvelto
https://github.com/mozilla-firefox/firefox/commit/5e9ec8cac2e6
https://hg.mozilla.org/integration/autoland/rev/9f7313ce5780
mozcrash: use symbols in binaries for local builds r=gsvelto

Comment 9

[Simon Chopin [:schopin]]

I'll just wait for a bit to make sure it doesn't get backed out, then I'll write the email.

Comment 10

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/30f93cd82865
https://hg.mozilla.org/mozilla-central/rev/9f7313ce5780

Comment 11

[Emilio Cobos Álvarez [:emilio]]

This is great! I guess no more piping through fix_stacks?

Comment 12

[Gabriele Svelto [:gsvelto]]

Not for local builds