I have upgraded HHVM on the CI slaves from 3.3.1+dfsg1-1+wm3.1 to 3.6.1+dfsg1-1+wm2 and mediawiki/core tests started to fail:
```
HHVM 3.6.1 is installed.
There were 7 errors:
1) WfBaseConvertTest::testDigitToBase2 with data set #0 ('0', '0', '0', '0', '0', '0', '0')
gmp_init(): Unable to convert variable to GMP - string is not an integer
includes/GlobalFunctions.php:3356
tests/phpunit/includes/GlobalFunctions/wfBaseConvertTest.php:53
tests/phpunit/MediaWikiTestCase.php:131
2) WfBaseConvertTest::testDigitToBase3 with data set #0 ('0', '0', '0', '0', '0', '0', '0')
gmp_init(): Unable to convert variable to GMP - string is not an integer
includes/GlobalFunctions.php:3356
tests/phpunit/includes/GlobalFunctions/wfBaseConvertTest.php:65
tests/phpunit/MediaWikiTestCase.php:131
3) WfBaseConvertTest::testDigitToBase5 with data set #0 ('0', '0', '0', '0', '0', '0', '0')
gmp_init(): Unable to convert variable to GMP - string is not an integer
includes/GlobalFunctions.php:3356
tests/phpunit/includes/GlobalFunctions/wfBaseConvertTest.php:77
tests/phpunit/MediaWikiTestCase.php:131
4) WfBaseConvertTest::testDigitToBase8 with data set #0 ('0', '0', '0', '0', '0', '0', '0')
gmp_init(): Unable to convert variable to GMP - string is not an integer
includes/GlobalFunctions.php:3356
tests/phpunit/includes/GlobalFunctions/wfBaseConvertTest.php:89
tests/phpunit/MediaWikiTestCase.php:131
5) WfBaseConvertTest::testDigitToBase10 with data set #0 ('0', '0', '0', '0', '0', '0', '0')
gmp_init(): Unable to convert variable to GMP - string is not an integer
includes/GlobalFunctions.php:3356
tests/phpunit/includes/GlobalFunctions/wfBaseConvertTest.php:101
tests/phpunit/MediaWikiTestCase.php:131
6) WfBaseConvertTest::testDigitToBase16 with data set #0 ('0', '0', '0', '0', '0', '0', '0')
gmp_init(): Unable to convert variable to GMP - string is not an integer
includes/GlobalFunctions.php:3356
tests/phpunit/includes/GlobalFunctions/wfBaseConvertTest.php:113
tests/phpunit/MediaWikiTestCase.php:131
7) WfBaseConvertTest::testDigitToBase36 with data set #0 ('0', '0', '0', '0', '0', '0', '0')
gmp_init(): Unable to convert variable to GMP - string is not an integer
includes/GlobalFunctions.php:3356
tests/phpunit/includes/GlobalFunctions/wfBaseConvertTest.php:125
tests/phpunit/MediaWikiTestCase.php:131
--
There was 1 failure:
1) IPTCTest::testIPTCParseForcedUTFButInvalid
Failed asserting that two arrays are equal.
--- Expected
+++ Actual
@@ @@
Array (
- 0 => 'ø'
+ 0 => ''
)
```
So it seems we have regressions in both IPTC and GMP.