PHPCS gets stuck creating file list when processing circular symlinks

[reedy]

This is fine on PHP_CodeSniffer 2.9.0, but on 3.1.1, running phpcs on this repo it gets stuck on Creating file list...

To reproduce:

git clone https://gerrit.wikimedia.org/r/operations/mediawiki-config
cd mediawiki-config
git fetch https://gerrit.wikimedia.org/r/operations/mediawiki-config refs/changes/65/367465/15 && git cherry-pick FETCH_HEAD
git submodule update --init --recursive
php composer.phar update
php multiversion/vendor/bin/phpcs -vvv .

Then it'll get to

Registered PHP_CodeSniffer\Standards\Squiz\Sniffs\WhiteSpace\SuperfluousWhitespaceSniff
Registered PHP_CodeSniffer\Standards\Zend\Sniffs\Files\ClosingTagSniff
Registered PHP_CodeSniffer\Standards\Generic\Sniffs\PHP\BacktickOperatorSniff
Creating file list... 

In our CI, we get it timing out after 10 minutes

20:49:09   [Symfony\Component\Process\Exception\ProcessTimedOutException]     
20:49:09   The process "composer phpcs" exceeded the timeout of 600 seconds. 

Originally, we had some issues relating to symlinks, https://phabricator.wikimedia.org/T171510 which I think was "fixed" in #1438 (errors being the same "No PHP code was found in this file" etc) and therefore edcca45

Did that break something? The repo has quite a few symlinks...

Downstream task for this is https://phabricator.wikimedia.org/T181262

[gsherwood]

Might have something to do with it:

$ cd mediawiki-config/portals/prod/wikimedia.org
$ ls -la
total 16
drwxr-xr-x+  4 gsherwood  staff   128 24 Nov 08:31 .
drwxr-xr-x+ 10 gsherwood  staff   320 24 Nov 08:31 ..
-rw-r--r--+  1 gsherwood  staff  7861 24 Nov 08:31 index.html
lrwxr-xr-x   1 gsherwood  staff     2 24 Nov 08:31 portal -> ..

PHPCS follows symlinks and it looks to be getting stuck around here. I'll see what I can do, but adding --ignore=*/portal/* to the CLI gets it going for now.

[reedy]

Ah, yes. That mess, I'd forgotten about that piece of work. Fresh pair of eyes is always useful, thanks!

Long filed over at https://phabricator.wikimedia.org/T151685

Let's add it to exclude-pattern

Cheers

[gsherwood]

Let's add it to exclude-pattern

Good idea, although I will still try and fix this.

[reedy]

That'd be great if you could 👍

[gsherwood]

I've had to re-introduce the realpath check and record already accepted paths, but it gets it working.

Thanks for the report.