Improve error handling and printed output of `flatpak-coredumpctl` by electricbrass · Pull Request #6649 · flatpak/flatpak

electricbrass · 2026-05-06T23:22:14Z

This is the first of a few planned PRs to fix and improve flatpak-coredumpctl.

Changes made by this PR:

Strings are now consistently quoted with double quotes. They were very inconsistent before. I chose double quotes because they seemed a bit more common throughout the file, and there were more strings that contained single quotes inside the string than the other way around.
printf-style format strings have been replaced with f-strings for readability.
When printing the flatpak command, shlex.join is used to present a more readable output.

Before:

Running: `"flatpak" "run" "--filesystem=home" "--filesystem=/tmp" "--command=gdb" "--devel" "net.odamex.Odamex" "/app/bin/odamex" "/tmp/tmpwhotdzk2"`

After:

Running: `flatpak run --filesystem=home --filesystem=/tmp --command=gdb --devel net.odamex.Odamex /app/bin/odamex /tmp/tmpgn2_hiwl`

The ""Executable [exe] doesn't seem to be a flatpaked application." error message is now only printed if the path does not start with "/newroot" or "/app". Previously it only checked for "/newroot", which is no longer present, due to changes in bwrap. This meant the warning was printed out even if the executable was in a Flatpak.
When running coredumpctl dump, exceptions are now caught, with the error message from coredumpctl being printed out. Previously the exception was uncaught, leading to the output seen in [Bug]: flatpak-coredumpctl crashes when -m is provided with an invalid argument. #6270.
Similarly, the flatpak command uses subprocess.run instead of subprocess.check_call. Instead of raising an exception, it calls sys.exit with the return code from the flatpak command.

I couldn't find any documentation anywhere about the targeted Python version for flatpak-coredumpctl or flatpak-bisect. The changes in this PR have a minimum required version of 3.8 because of shlex.join and f-strings. The current version is compatible with down to 3.3.

Example output:
Flatpak does not exist/is not installed:

-m finds no matches:

bbhtt

commits should be prefixed by flatpak-coredumpctl: and the length needs to be <=72 chars. Also make sure to put some description where suitable about what and why of the change (linking issues etc. or your personal opinion).

bbhtt · 2026-05-07T12:03:46Z

    options = parser.parse_args(namespace=coredumper)
    if not coredumper.clean_args():
-        parser.print_help()
+        parser.print_help(sys.stderr)


should explain why this is being changed.

In most programs that print the help message due to missing/incorrect arguments, it gets printed to stderr instead of stdout. I'm cleaning up the commit messages now and will add this to the description.

bbhtt · 2026-05-07T12:34:50Z

I couldn't find any documentation anywhere about the targeted Python version for flatpak-coredumpctl or flatpak-bisect.

The build indeed does not define a minimum version and there aren't any runtime checks in the scripts either. Maybe it should have one or both of those.

If the minimum is getting raised, this cannot be backported to 1.16.x. If that's ok, and it's going to land in the unstable and new stable 1.18.x, I think using upto 3.10 is ok if that's what you need. I'm sceptical about supporting EOL Python versions.

electricbrass · 2026-05-12T21:24:21Z

the length needs to be <=72 chars

Is that the total length including the flatpak-coredumpctl:?

electricbrass · 2026-05-12T21:29:45Z

If the minimum is getting raised, this cannot be backported to 1.16.x. If that's ok, and it's going to land in the unstable and new stable 1.18.x, I think using upto 3.10 is ok if that's what you need. I'm sceptical about supporting EOL Python versions.

My intention was for this to go to 1.17/1.18. If you would rather it be able to go into 1.16, I can revert the changes that raised the minimum version, but it would definitely be nicer to be able to use 3.10.

swick · 2026-05-13T00:33:23Z

Is that the total length including the flatpak-coredumpctl:?

Including the prefix

If you would rather it be able to go into 1.16, I can revert the changes

I will be releasing 1.18 very soon at which point 1.16 won't be supported anymore anyway, so I'd say don't bother.

bbhtt · 2026-05-13T04:31:56Z

My intention was for this to go to 1.17/1.18.

Yes I suggest then using 3.10 to make life easier. And also encoding the requirement formally in meson.build + runtime verification.

electricbrass · 2026-05-17T19:05:22Z

encoding the requirement formally in meson.build

I'm not particularly familiar with meson. Would something like this in scripts/meson.build be correct?

py = import('python').find_installation('python3')
pyver = py.language_version()
if pyver.version_compare('<3.10')
  error('Python >= 3.10 is required, found ' + pyver)
endif

(And then since this affects flatpak-bisect as well, should I go ahead and put the runtime check in there too even though I'm otherwise not touching it?)

bbhtt · 2026-05-19T02:17:32Z

I'm not particularly familiar with meson. Would something like this in scripts/meson.build be correct?

Yes something like that.

should I go ahead and put the runtime check in there too even though I'm otherwise not touching it?)

In a later PR when it is actually relying on 3.10 features. Same for the meson.build part.

bbhtt · 2026-05-19T03:42:57Z

A few of your commits are still exceeding the width.

electricbrass · 2026-05-19T03:47:53Z

It looks to me like the longest is 70 characters?

Edit: Oh wait found one description line that was too long.

This fixes a bug where the warning about not being a flatpaked application was being printed for flatpaks. This was due to a change in bwrap so that the paths no longer start with /newroot.

Print out error messages instead of raising an uncaught exception Replace one more set of quotes that I missed previously

This is more consistent with common practice for help messages printed due to missing/incorrect arguments.

This prevents it from getting printed twice in some circumstances

bbhtt · 2026-05-19T03:51:40Z

It's in body:

git commitlen HEAD~10..HEAD                                                                                                                                               
6ff20ceb flatpak-coredumpctl: Print help message to stderr
  line 3: 106 chars: This is more consistent with common practice for help messages printed due to missing/incorrect arguments.

electricbrass force-pushed the coredumpctl-fixes branch from bbe777c to 3d1d780 Compare May 6, 2026 23:22

bbhtt reviewed May 7, 2026

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Comment thread scripts/flatpak-coredumpctl Outdated

bbhtt reviewed May 7, 2026

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Comment thread scripts/flatpak-coredumpctl Outdated

electricbrass force-pushed the coredumpctl-fixes branch 2 times, most recently from f3723c2 to 1463ac6 Compare May 12, 2026 21:41

electricbrass force-pushed the coredumpctl-fixes branch 2 times, most recently from 74a3351 to 15f2451 Compare May 17, 2026 19:46

bbhtt assigned bbhtt and unassigned bbhtt May 19, 2026

electricbrass added 9 commits May 18, 2026 22:48

flatpak-coredumpctl: Check for /app as well as /newroot

9b4973b

This fixes a bug where the warning about not being a flatpaked application was being printed for flatpaks. This was due to a change in bwrap so that the paths no longer start with /newroot.

flatpak-coredumpctl: Clean up mixed usage of single and double quotes

13624fe

flatpak-coredumpctl: Replace old style format strings with f-strings

83fe815

Print out error messages instead of raising an uncaught exception Replace one more set of quotes that I missed previously

flatpak-coredumpctl: Print help message to stderr

cc769ab

This is more consistent with common practice for help messages printed due to missing/incorrect arguments.

flatpak-coredumpctl: Exit with return code of flatpak_command

f350ef8

flatpak-coredumpctl: Pass description as argparse description argument

90da09a

This prevents it from getting printed twice in some circumstances

flatpak-coredumpctl: Pass tuple to startswith instead of two calls

e942fe1

flatpak-coredumpctl: Require Python 3.10 or greater at runtime

9cdb1be

flatpak-coredumpctl: Use subprocess.PIPE instead of NamedTemporaryFile

21273c6

electricbrass force-pushed the coredumpctl-fixes branch from 3444e9e to 21273c6 Compare May 19, 2026 03:50

swick added this pull request to the merge queue May 27, 2026

Merged via the queue into flatpak:main with commit 8c418fa May 27, 2026
11 checks passed

LuckShiba mentioned this pull request May 29, 2026

Flatpak: NixOS-integrated Flatpak package management NixOS/nixpkgs#347605

Open

2 of 13 tasks

electricbrass deleted the coredumpctl-fixes branch May 31, 2026 02:25

mcatanzaro mentioned this pull request Jun 8, 2026

[Bug]: Flatpak Coredumpctl Crash #5244

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4 tasks done

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