GDB breakpoint and step on chained method

help
1

I'm new to GDB but understand some debug keywords and flow. When I'm debugging Rust, I can create breakpoint, step in, step out, next just fine. But, it doesn't work when having a chain of methods:

    let webview = WebViewBuilder::new()
        .with_bounds(Rect {
            position: LogicalPosition::new(0, 0).into(),
            size: LogicalSize::new(10, 10).into(),
        })
        .with_transparent(true)
        .with_url("https://www.rust-lang.com/")
        .with_html(
            r#"<html>
                    <body style="background-color: #f05; width: 100vw; height: 100vh">
                        <p>A paragraph</p>
                    </body>
                </html>"#,
        )
        .build_gtk(&root_gtk_box)
        .unwrap();

I can't exactly "pause" at build_gtk line, whether by using breakpoint or step one by one.

Is this GDB limitation? Is there any tricks?