missing skin.json error with MediaWiki 1.26

[MartinsZieds]

When you're doing:
php maintenance/update.php

Then the PHP is shouting:
PHP Fatal error: Uncaught exception 'Exception' with message '/var/www/wiki/skins/bootstrap-mediawiki/skin.json does not exist!' in /var/www/wiki/includes/registration/ExtensionRegistry.php:106

Any ideas how to create that file?

[ZerooCool]

I see the file Makefile but i not use it. It's the good way, i don't know. Sorry.

[mervit]

I have same issue. U must compile skin with grunt.
After this u will have skin.js in your directory.