What does the Gulp error "Function did not return a value" mean when building a sass project?

Question

css

to create a grid, I use the
sass-mq
library, but when building, gulp constantly swears at an error:

Error: Function mq-get-breakpoint-width did not return a value
on line 182 of css/sass-mq.scss
$min-width: mq-px2em(mq-get-breakpoint-width($from, $breakpoints))

tried to replace the file with the original one, googled the options, but it was not possible to fix the problem
due to an error, the project is not going to the end

Answer 1

solution - I included the files in the wrong order. and when it came to sass-mq, this file used variables that should have been written before this file.

Answer 2

Make sure the mixin specifies return.