I don't know if this has to do with the WMCS outage, but in https://gerrit.wikimedia.org/r/c/mediawiki/core/+/490308#message-c5e8a6d7c284267e7a8f531e5c6b6eea9ce4547d most of the tests failed. The failures are all due to npm, as far as I can tell its cache is corrupted. Some extracts from the various tests there:
```
11:22:56 + npm install --no-progress
11:22:59 npm ERR! Linux 4.9.0-0.bpo.8-amd64
11:22:59 npm ERR! argv "/usr/bin/nodejs" "/usr/local/bin/npm" "install" "--no-progress"
11:22:59 npm ERR! node v6.11.0
11:22:59 npm ERR! npm v3.8.3
11:22:59 npm ERR! file /cache/json-stable-stringify-without-jsonify/1.0.1/package/package.json
11:22:59 npm ERR! code EJSONPARSE
11:22:59
11:22:59 npm ERR! Failed to parse json
11:22:59 npm ERR! Unexpected token 'b' at 1:1
11:22:59 npm ERR! b9761e09d397bdda699fee454c327946ec1240aa
11:22:59 npm ERR! ^
11:22:59 npm ERR! File: /cache/json-stable-stringify-without-jsonify/1.0.1/package/package.json
11:22:59 npm ERR! Failed to parse package.json data.
11:22:59 npm ERR! package.json must be actual JSON, not just JavaScript.
11:22:59 npm ERR!
11:22:59 npm ERR! This is not a bug in npm.
11:22:59 npm ERR! Tell the package author to fix their package.json file. JSON.parse
```
```
11:25:42 npm ERR! Failed to parse json
11:25:42 npm ERR! Unexpected token '\u0000' at 1:2752
11:25:42 npm ERR! ted-git-info@>=2.1.4 <3.0.0","readme":"ERROR: No README data found!"}
11:25:42 npm ERR! ^
11:25:42 npm ERR! File: /cache/npm/espree/5.0.0/package/package.json
11:25:42 npm ERR! Failed to parse package.json data.
11:25:42 npm ERR! package.json must be actual JSON, not just JavaScript.
11:25:42 npm ERR!
11:25:42 npm ERR! This is not a bug in npm.
11:25:42 npm ERR! Tell the package author to fix their package.json file. JSON.parse
```
```
11:23:48 npm ERR! Linux 4.9.0-0.bpo.8-amd64
11:23:48 npm ERR! argv "/usr/bin/nodejs" "/usr/local/bin/npm" "install"
11:23:48 npm ERR! node v6.11.0
11:23:48 npm ERR! npm v3.8.3
11:23:48 npm ERR! code EISDIR
11:23:48 npm ERR! errno -21
11:23:48 npm ERR! syscall read
11:23:48
11:23:48 npm ERR! eisdir EISDIR: illegal operation on a directory, read
11:23:48 npm ERR! eisdir This is most likely not a problem with npm itself
11:23:48 npm ERR! eisdir and is related to npm not being able to find a package.json in
11:23:48 npm ERR! eisdir a package you are trying to install.
```
```
11:23:51 npm ERR! addLocal Could not install /workspace/src/tests/selenium/wdio-mediawiki
11:23:51 npm ERR! Linux 4.9.0-0.bpo.8-amd64
11:23:51 npm ERR! argv "/usr/bin/nodejs" "/usr/local/bin/npm" "install"
11:23:51 npm ERR! node v6.11.0
11:23:51 npm ERR! npm v3.8.3
11:23:51 npm ERR! path /cache/npm/wdio-mediawiki/0.3.0/package
11:23:51 npm ERR! code ENOTDIR
11:23:51 npm ERR! errno -20
11:23:51 npm ERR! syscall mkdir
11:23:51
11:23:51 npm ERR! ENOTDIR: not a directory, mkdir '/cache/npm/wdio-mediawiki/0.3.0/package'
```