Special:Version is using is_file() to check if $wgGitBin is set to a valid git binary path, but that produces a warning if there's an open_basedir restriction in effect. This only happens when there are extensions installed downloaded from git.
We should probably use error handling to prevent that warning from popping up.
Steps to reproduce:
- Download an extension from Gerrit.
- Example: go to the extensions directory and use git clone https://gerrit.wikimedia.org/r/p/mediawiki/extensions/UserMerge
- Load the extension in LocalSettings.php.
- Example: wfLoadExtension( 'UserMerge' );
- Be sure php.ini has open_basedir set to MediaWiki install directory, and probably a temp directory like /tmp
- Go to Special:Version and it should display the warning (if your error_reporting configuration is not hiding it).
Original Version: 1.23.5
Latest version reproduced: 1.29-rc0