This warning seems to have started with the 1.29.0-wmf.10 deploy.
Here is not much more information in logstash than is provided by the warning message: https://logstash.wikimedia.org/goto/ddb4c133e05d33fe6ecb3de91324090e
Description
Description
Details
Details
| Subject | Repo | Branch | Lines +/- | |
|---|---|---|---|---|
| Log a backtrace from the culprit location if headers were already sent | mediawiki/core | master | +77 -32 |
| Status | Subtype | Assigned | Task | ||
|---|---|---|---|---|---|
| Resolved | PRODUCTION ERROR | tstarling | T157392 Warning: Cannot modify header information - headers already sent in /srv/mediawiki/php-1.29.0-wmf.10/includes/WebResponse.php on line 45 | ||
| Duplicate | PRODUCTION ERROR | None | T158270 PHP warnings should be logged via Monolog (with a stack trace), not HHVM |
Event Timeline
Comment Actions
HHVM supports header_register_callback(), so it would be easy enough to log a backtrace collected from the point where headers were initially sent.
Comment Actions
Change 338705 had a related patch set uploaded (by Tim Starling):
Log a backtrace from the culprit location if headers were already sent
Comment Actions
Change 338705 merged by jenkins-bot:
Log a backtrace from the culprit location if headers were already sent
Comment Actions
I got similar error report in MW 1.28.2.
"PHP message: PHP Warning: Cannot modify header information - headers already sent by (output started at /var/www/wiki/includes/actions/RawAction.php:115) in /var/www/wiki/includes/WebResponse.php on line 45
Is there any fast fix for MW 1.28?
I tried to replace some file from https://gerrit.wikimedia.org/r/#/c/338705/. But my wiki crash.