Zend certified PHP/Magento developer

@baseDir variable not working in less file for background-image. Says undefined

Several other questions/answers here say to use the variable @{baseDir} to get the url for background-image. I added this to my themes less file, however when I compile, it crashes.

variable @baseDir is undefined

I do not understand how to proceed. I found several other files that have the reference to baseDir and it works fine, but in this specific less file, it doesn’t. Frustrated.