investigate flaky internet/test-dns-idna2008 test
test/internet/test-dns-idna2008.js (added in four days ago when #25679 landed) failed in CI a few hours ago:
https://ci.nodejs.org/job/node-test-commit-custom-suites/855/default/console
Host: test-rackspace-ubuntu1604-x64-2
00:01:48 not ok 9 internet/test-dns-idna2008 00:01:48 --- 00:01:48 duration_ms: 1.14 00:01:48 severity: fail 00:01:48 exitcode: 1 00:01:48 stack: |- 00:01:48 (node:4568) ExperimentalWarning: The dns.promises API is experimental 00:01:48 assert.js:753 00:01:48 throw newErr; 00:01:48 ^ 00:01:48 00:01:48 AssertionError [ERR_ASSERTION]: ifError got unwanted exception: queryA ESERVFAIL straße.de 00:01:48 at QueryReqWrap.dns.resolve4.mustCall (/home/iojs/build/workspace/node-test-commit-custom-suites/default/test/internet/test-dns-idna2008.js:27:10) 00:01:48 at QueryReqWrap.callback (/home/iojs/build/workspace/node-test-commit-custom-suites/default/test/common/index.js:368:15) 00:01:48 at QueryReqWrap.onresolve [as oncomplete] (dns.js:199:10) 00:01:48 at QueryReqWrap.onresolve [as oncomplete] (dns.js:199:19) 00:01:48 ...
It had previously succeeded in CI (see https://ci.nodejs.org/job/node-test-commit-custom-suites/852/default/console).
I guess ESERVFAIL is a DNS problem likely unrelated to the test itself? Although other DNS tests in internet ran just fine, so maybe it is in fact specific to this test?