panic message is not a string literal

[sebastianv89]

Running the OS tutorial (https://os.phil-opp.com/), I get a warning every time I run the OS. I traced back the issue to this line:

bootloader/build.rs

Line 128 in 6a8a263

format!("KERNEL does not exist: {}", kernel.display())

This is the warning:

warning: panic message is not a string literal
   --> build.rs:128:9
    |
128 |         format!("KERNEL does not exist: {}", kernel.display())
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(non_fmt_panic)]` on by default
    = note: this is no longer accepted in Rust 2021
    = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

I run the following versions:

$ cargo --version
cargo 1.52.0-nightly (bf5a5d5e5 2021-02-18)
$ rustc --version
rustc 1.52.0-nightly (9b471a3f5 2021-02-19)
$ bootimage --version
bootimage 0.10.2

[phil-opp]

Thanks for reporting! Should be fixed with #138, which was released as v0.9.13.