Bug 319698 – [WKCI] filter-test-logs crashes on output that is not valid UTF-8, and loses the tail of the log when the step is killed

• Status: RESOLVED
• Resolution: FIXED
• Component: Tools / Tests

[Carlos Alberto Lopez Perez]

filter-test-logs has two robustness problems:

1. It crashes (UnicodeEncodeError or UnicodeDecodeError, depending on the system locale) when the test output contains text that is not valid UTF-8. This can be garbage bytes from a crashing test process, or lone unicode surrogates from WPT tests that use intentionally malformed text on purpose (to check that the browser handles it well). When the filter crashes, the log file is cut short and the test command starts failing with broken pipe errors, so the whole step fails in a confusing way. There is a workaround for this from 300617@main, but it only covers the layout filter, and it works by silently dropping the problematic lines from the log, which are often exactly the lines you want to see when investigating.

2. The log file is written with the default buffering, so when buildbot kills the step, the last lines received (whatever was sitting in the write buffer, up to 8 KB) are lost from the log that gets uploaded to S3.

[Carlos Alberto Lopez Perez]

Pull request: https://github.com/WebKit/WebKit/pull/69673

[Radar WebKit Bug Importer]

<rdar://problem/183159176>

[EWS]

Committed 317900@main (f98b3f2b9488): <https://commits.webkit.org/317900@main>

Reviewed commits have been landed. Closing PR #69673 and removing active labels.