# How to fix a PR's failing checks
### tree-status
Unlike other checks, **tree-status** isn't tied to the pull request:
instead, it shows whether checks are passing in the main branch.\
Failures can happen for a variety of reasons and should be addressed
before anything else is merged in.
**What to do:** Once [review requirements](../Tree-hygiene.md#getting-a-code-review)
are met and all other checks are passing, a reviewer will add the
[**`autosubmit`**](../../infra/Landing-Changes-With-Autosubmit.md) label,
and then a bot will merge the PR once **tree-status** succeeds.
### Google testing
A Google testing failure could be a flake ([see below](#flaking)), or it
might be due to changes in the PR (See
[Understanding Google Testing](../../infra/Understanding-Google-Testing.md)
for more info).
Google employees can view the test output and give feedback accordingly.
**What to do:** If 2 weeks have gone by and nobody's looked into it,
feel free to [reach out on Discord](../Chat.md).
### ci.yaml validation
In order for checks to run correctly, the [.ci.yaml](../../../.ci.yaml)
file needs to stay in sync with the base branch.
**What to do:** This check failure can be fixed by applying the latest changes
from master.\
(The [Tree hygiene](../Tree-hygiene.md#using-git) page recommends updating
via rebase, rather than a merge commit.)
## A bug in the PR
Oftentimes, a change inadvertently breaks expected behavior.\
When this happens, usually the best way to find out what's wrong is to
[**view the test output**](#view-the-test-output).
If a **customer_testing** check is unsuccessful, it's a signal that something in the
[Flutter customer test registry](https://github.com/flutter/tests/) has failed.
This includes [package tests](../../ecosystem/testing/Understanding-Packages-tests.md)
along with other tests from open-source Flutter projects.\
If a pull request requires an update to those external tests, it qualifies as a
[**breaking change**](../Tree-hygiene.md#handling-breaking-changes);
please avoid those when possible.
If **Linux Analyze** fails, it's likely that one or more changes in the PR
violated a [linter rule](https://dart.dev/lints/).\
Consider reviewing the steps outlined in
[setting up the framework dev environment](../../Setting-up-the-Framework-development-environment.md)
so that most of these problems get caught in static analysis right away.
> [!NOTE]
> All Dart code is run through static analysis:
> this includes markdown code snippets in doc comments!
>
> See [Hixie's Natural Log](https://ln.hixie.ch/?start=1660174115) for more details.
### View the test output
Click on **Details** for the failing test, and then click
**View more details on flutter-dashboard**.
The full test output is linked at the bottom of the page.
Often, there will be a message that resembles the one below:
```
══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
The following TestFailure was thrown running a test:
Expected: exactly one matching candidate
Actual: _TextWidgetFinder:(ConnectionState.waiting, null, null, null)": []>
Which: means none were found but one was expected
When the exception was thrown, this was the stack:
#4 main.. (…/packages/flutter/test/widgets/async_test.dart:115:7)
#5 testWidgets.. (package:flutter_test/src/widget_tester.dart:189:15)
#6 TestWidgetsFlutterBinding._runTestBody (package:flutter_test/src/binding.dart:1032:5)
(elided one frame from package:stack_trace)
This was caught by the test expectation on the following line:
file:///b/s/w/ir/x/w/flutter/packages/flutter/test/widgets/async_test.dart line 115
The test description was:
gracefully handles transition from null future
════════════════════════════════════════════════════════════════════════════════════════════════════
```
From there, it's just a matter of finding the failing test,
[running it locally](./Running-and-writing-tests.md),
and figuring out how to fix it!
### Flaking
A check might "flake", or randomly fail, for a variety of reasons.
Sometimes a flake resolves itself after changes are pushed to re-trigger
the checks. Consider [performing a rebase](#ciyaml-validation) to include
the latest changes from the main branch.
Flakes often happen due to **infra errors**.
For information on how to view and report infrastructure bugs, see the
[infra failure overview](../../infra/Understanding-a-LUCI-build-failure.md#overview-of-an-infra-failure-build).