calc() dont work!

[ghost]

When i trying to compile width: clac(100% - 50px), i some times can see thar result:

[Krinkle]

Looks like this is a bug (or feature) in Less.js upstream. Please report upstream at https://github.com/less/less.js.

Trying on http://less2css.org/

.test-1 {
    margin: calc(100% - 50px);
}

.test-1 {
  margin: calc(50%);
}