Cargo run忽略指定给cargo构建的功能

Question

我是这样编译Rust GTK examples的：

$ cargo build --features gtk_3_10

当我尝试运行该示例时，发生了一个错误：

   $ cargo run --bin gtktest   
    Compiling gtk-rs-examples v0.0.1 (file:///home/me123/rust/gtk_examples)
    Finished dev [unoptimized + debuginfo] target(s) in 0.39 secs
     Running `target/debug/gtktest`
This example only work with GTK 3.10 and later
Did you forget to build with `--features gtk_3_10`?

如何解决这个问题？