$ cd app
```
-Step number one is to set a default compilation target in `.cargo/config`.
+Step number one is to set a default compilation target in `.cargo/config.toml`.
``` console
-tail -n5 .cargo/config
+tail -n5 .cargo/config.toml
```
``` toml
Alternatively, you can turn `<gdb> -x openocd.gdb` into a custom runner to make
`cargo run` build a program *and* start a GDB session. This runner is included
-in `.cargo/config` but it's commented out.
+in `.cargo/config.toml` but it's commented out.
``` console
-head -n10 .cargo/config
+head -n10 .cargo/config.toml
```
``` toml