It tends to be under 5 seconds or between 2 to 5 minutes. I couldn't find a sample of one longer than 3 minutes, but I've definitely seen them.
https://integration.wikimedia.org/ci/job/mediawiki-phpunit-hhvm/6376/consoleFull
(duration: 2s)
00:00:12.249 You can install MediaWiki. 00:00:12.251 Setting up database 00:00:12.355 done 00:00:12.356 Creating tables 00:00:14.843 done
https://integration.wikimedia.org/ci/job/mediawiki-phpunit-hhvm/6389/consoleFull
(duration: 1m17s)
00:00:19.584 You can install MediaWiki. 00:00:19.585 Setting up database 00:00:19.622 done 00:00:19.622 Creating tables 00:01:36.238 done
https://integration.wikimedia.org/ci/job/mediawiki-phpunit-hhvm/6390/consoleFull
(duration: 2m46s)
00:00:24.617 You can install MediaWiki. 00:00:24.618 Setting up database 00:00:24.659 done 00:00:24.661 Creating tables 00:01:01.998 [Thu Apr 16 03:08:28 2015] [hphp] [27994:7f86ecc1abc0:0:000001] [] SlowTimer [11043ms] at runtime/ext_mysql: slow query: CREATE /* DatabaseBase::sourceFile( /mnt/jenkins-workspace/workspace/mediawiki-phpunit-hhvm@2/src/maintenance/tables.sql ) 127.0.0.1 */ INDEX page_timestamp ON `revision` (rev_page,rev_timestamp) 00:01:01.998 00:01:14.379 [Thu Apr 16 03:08:41 2015] [hphp] [27994:7f86ecc1abc0:0:000002] [] SlowTimer [12380ms] at runtime/ext_mysql: slow query: CREATE /* DatabaseBase::sourceFile( /mnt/jenkins-workspace/workspace/mediawiki-phpunit-hhvm@2/src/maintenance/tables.sql ) 127.0.0.1 */ INDEX user_timestamp ON `revision` (rev_user,rev_timestamp) 00:01:14.379 00:03:10.550 done
https://integration.wikimedia.org/ci/job/mediawiki-phpunit-hhvm/6392/consoleFull
(duration: 1s)
00:00:07.482 You can install MediaWiki. 00:00:07.483 Setting up database 00:00:07.516 done 00:00:07.516 Creating tables 00:00:08.961 done
https://integration.wikimedia.org/ci/job/mediawiki-phpunit-hhvm/6395/consoleFull
(duration: 36s)
00:00:14.645 You can install MediaWiki. 00:00:14.645 Setting up database 00:00:14.683 done 00:00:14.684 Creating tables 00:00:50.095 done
https://integration.wikimedia.org/ci/job/mediawiki-phpunit-hhvm/6402/consoleFull
(duration: 2s)
00:00:12.024 You can install MediaWiki. 00:00:12.026 Setting up database 00:00:12.068 done 00:00:12.069 Creating tables 00:00:14.399 done