The REL1_19 parserTests are broken. The very first test takes can take more than two second to startup which make the test to timeout.
Example trouble: https://gerrit.wikimedia.org/r/#/c/30834/
According to my local testing that might be due to the language cache being populated on the first test. The cache needs to be prepopulated before the tests begins.
Version: unspecified
Severity: blocker
On my laptop using an SSD:
0.2645 30.0M LocalisationCache::recache writing cache for 'en'
1.3191 41.5M LocalisationCache::recache finished writing cache for 'en'
A bit more than a second, so if that is being done on the first test, that is definitely the root cause.
The workaround is to raise the PHP timeout for parser tests to 10 seconds like we have done in 1.20. Backported the change in REL1_19 with https://gerrit.wikimedia.org/r/#/c/30908/