LYR-SEM0072
an import that is never used
A name an import binds is never referred to in the file.
Explanation
An unused import makes the file look as if it depended on a module it does not need. A module import counts as used when an extension method of that module, or of a module it passes on with pub import, is called in the file.
Remove the import, or the name from the import list. An import brings its module's extend blocks along with its names, so where no name of import std.io { Writer }; is used but the file calls writeAll, a method those blocks add, the warning says to keep the module alone: import std.io;. Removing the import there would take the method away (LYR-SEM0012). The warning says to take the import out where another import or the prelude brings the same blocks.
A constraint a type satisfies through a conformance names nothing of the module that gives it. Where the module declares neither the type nor the interface, and no other import brings the module, lyric fix leaves the import alone and the warning says what depends on it.
Wrong
import std.io { println };
fn main(): void {
}Right
fn main(): void {
}