Mixin parameters can't be used in import statements

[lipis]

When trying to compile the following

@web-font-path: "https://fonts.googleapis.com/css?family=Roboto:300,400,500,700";

.web-font(@path) {
  @import url("@{path}");
}
.web-font(@web-font-path);

https://github.com/thomaspark/bootswatch/blob/v3.3.7/cosmo/bootswatch.less#L5-L10

I'm getting this error:

$ ./node_modules/less/bin/lessc cosmo/bootswatch.less
SyntaxError: variable @path is undefined in /Users/lipis/bootswatch/cosmo/bootswatch.less on line 10, column 1:
9 }
10 .web-font(@web-font-path);
11

---

Less version: 3.0.4 / macOS

[seven-phases-max]

See #2772.

[seven-phases-max]

Closing as duplicate of #2772.