Documentation error. Please fix it.

[Bahurtsev]

On this page: https://lesscss.org/features/#extend-feature-extend-all

This example does not work:

.bucket { color: blue; } @{variable}:extend(.bucket) {} @variable: .selector;

compiles to:

.bucket, .selector { color: blue; }

You need to write it like this:

.bucket { color: blue; } @{variable} { &:extend(.bucket); } @variable: .selector;

compiles to:

.bucket, .selector { color: blue; }

As I understand it, LESS treats interpolation as "late binding", so :extend() cannot be applied to a selector that has not yet been formed at the parsing stage.