Tests failing with MySQL versions greater than 5.6.17, possibility to do with transactions?

[cookiesowns]

It appears that our test-suite leveraging WP_UnitTest cases are failing when MySQL is upgraded to a version greater than 5.6.17.

It's known to be failing on 5.7.11, as well as 5.6.2X. After some debugging it seems that this has to do with transactions not properly being handled, so if we interface with the database using WPDB manually, data remains from a previous test, thus breaking our test-suite.

I'm not sure how exactly to debug this, but will to help reproduce and resolve this issue.

All of the WP_UnitTest libraries are fully up to date from trunk.

[jdgrimes]

Can you isolate a particular test that we can use to reproduce this error? I have a feeling that something may be causing the transactions to be committed unexpectedly, but we can't be sure what it is until we identify the specific code needed to reproduce this bug.

[netweb]

WordPress' Travis CI tests now include a MySQL 5.6.x version in the test matrix, this is currently only the HHVM job:

• ​https://travis-ci.org/aaronjorbin/develop.wordpress/jobs/137440082

Currently this is MySQL 5.16.30 ​https://travis-ci.org/aaronjorbin/develop.wordpress/jobs/137440082#L501

At the moment though 1 test fails and another errors there are no issues using MySQL 5.6.30

[desrosj]

This appears that it was only an issue with HHVM jobs. Since ​support for HHVM was removed from WordPress in 2017 (and there has been a lack of reporter feedback), I’m going to close this out.