invalid_annotation

Annotation must be either a const variable reference or const constructor invocation.

The analyzer produces this diagnostic when an annotation is found that is using something that is neither a variable marked as const or the invocation of a const constructor.

Getters can't be used as annotations.

The following code produces this diagnostic because the variable v isn't a const variable:

var v = 0;
​
@v
void f() {
}

The following code produces this diagnostic because f isn't a variable:

@f
void f() {
}

The following code produces this diagnostic because f isn't a constructor:

@f()
void f() {
}

The following code produces this diagnostic because g is a getter:

@g
int get g => 0;

If the annotation is referencing a variable that isn't a const constructor, add the keyword const to the variable's declaration:

const v = 0;
​
@v
void f() {
}

If the annotation isn't referencing a variable, then remove it:

int v = 0;
​
void f() {
}