1export fn entry() void {
 2    foo(452) catch |err| switch (err) {
 3        error.Foo => {},
 4        error.Bar => {},
 5        error.Foo => {},
 6        else => {},
 7    };
 8}
 9fn foo(x: i32) !void {
10    switch (x) {
11        0...10 => return error.Foo,
12        11...20 => return error.Bar,
13        else => {},
14    }
15}
16
17// error
18//
19// :5:9: error: duplicate switch value
20// :3:9: note: previous value here