Topic on Skin talk:DarkVector

What is the best way to make a working copy of the current version of Vector that can then be adjusted?

I've enjoyed using DarkVector and wanted to try something similar (a skin based on Vector with cosmetic adjustments), but when I duplicate the current 1.37 Vector and change out the skin name in the code and file names, it produces internal errors like this:

Class 'AltVector\SkinVersionLookup' not found.
Backtrace: from /var/www/my.wiki/public_html/mediawiki-1.37.2/skins/AltVector/includes/ServiceWiring.php(55)
...

Thanks for any thoughts/suggestions!

I tried this a year or two ago and couldn't figure it out. Very frustrating. Something that I wish MediaWiki would improve on, like make it easier to fork a skin.

Honestly, that's a huge pain. I wish Vector skin has option to set custom colors, e.g. using CSS variables or something like that