Setup error: File not found for module arch

[jptrzy]

I'm trying to follow this book, but I stumbled on a quite annoying issue which I couldn't fix myself.

While compiling esp-backtrace via running cargo run --release I get this error:

...
error[E0583]: file not found for module `arch`
  --> /home/jp3/.cargo/registry/src/index.crates.io-6f17d22bba15001f/esp-backtrace-0.14.2/src/lib.rs:46:1
   |
46 | pub mod arch;
   | ^^^^^^^^^^^^^
   |
   = help: to create the module `arch`, create file "/home/jp3/.cargo/registry/src/index.crates.io-6f17d22bba15001f/esp-backtrace-0.14.2/src/arch.rs" or "/home/jp3/.cargo/registry/src/index.crates.io-6f17d22bba15001f/esp-backtrace-0.14.2/src/arch/mod.rs"
   = note: if there is a `mod arch` elsewhere in the crate already, import it with `use crate::...` instead

error[E0425]: cannot find function `backtrace` in module `crate::arch`
  --> /home/jp3/.cargo/registry/src/index.crates.io-6f17d22bba15001f/esp-backtrace-0.14.2/src/lib.rs:69:34
   |
69 |     let backtrace = crate::arch::backtrace();
   |                                  ^^^^^^^^^ not found in `crate::arch`

error[E0425]: cannot find value `RA_OFFSET` in module `crate::arch`
  --> /home/jp3/.cargo/registry/src/index.crates.io-6f17d22bba15001f/esp-backtrace-0.14.2/src/lib.rs:76:55
   |
76 |         println!("{}0x{:x}", RED, addr - crate::arch::RA_OFFSET);
   |                                                       ^^^^^^^^^ not found in `crate::arch`

Some errors have detailed explanations: E0425, E0583.
For more information about an error, try `rustc --explain E0425`.
error: could not compile `esp-backtrace` (lib) due to 3 previous errors
warning: build failed, waiting for other jobs to finish...

Source

main.rs:

#![no_std]
#![no_main]

use esp_backtrace as _;
use esp_hal::delay::Delay;
use esp_hal::prelude::*;
use log::info;

#[entry]
fn main() -> ! {
    esp_println::logger::init_logger_from_env();

    let delay = Delay::new();
    loop {
        info!("Hello world!");
        delay.delay(500.millis());
    }
}

rust-toolchain.toml:

[toolchain]
channel = "nightly"
components = ["rust-src"]
targets = ["riscv32imc-unknown-none-elf"]

Cargo.toml:

[package]
name = "new_psalm"
version = "0.1.0"
edition = "2021"
license = "MIT OR Apache-2.0"
resolver = "2"

[dependencies]
esp-backtrace = { version = "0.14.0", features = [
    "esp32",
    "exception-handler",
    "panic-handler",
    "println",
]}

esp-hal = { version = "0.21.0", features = [
    "esp32",
] }
esp-println = { version = "0.12.0", features = ["esp32", "log"] }
log = { version = "0.4.21" }
esp-alloc = { version = "0.5.0" }
embedded-io = "0.6.1"

heapless = { version = "0.8.0", default-features = false }
smoltcp = { version = "0.11.0", default-features = false, features = [
    "medium-ethernet",
    "proto-dhcpv4",
    "proto-igmp",
    "proto-ipv4",
    "socket-dhcpv4",
    "socket-icmp",
    "socket-raw",
    "socket-tcp",
    "socket-udp",
] }
 bleps = { git = "https://github.com/bjoernQ/bleps", package = "bleps", rev = "a5148d8ae679e021b78f53fd33afb8bb35d0b62e", features = [ "macros", "async"] }
critical-section = "1.2.0"

[profile.dev]
# Rust debug is too slow.
# For debug builds always builds with some optimization
opt-level = "s"


[profile.release]
codegen-units = 1        # LLVM can perform better optimizations using a single thread
debug = 2
debug-assertions = false
incremental = false
lto = 'fat'
opt-level = 's'
overflow-checks = false

I also saw discussion #1783, but I couldn't wrap my head around it.

PS. I'm new to embedded rust, so it might be some kind of dumb mistake.

[bugadani]

You seem to be targeting riscv32imc-unknown-none-elf in your toolchain.toml (which is esp32-c2 and c3), but esp32 (which is an xtensa architecture processor) in your Cargo.toml. Which MCU are you actually using?

[jptrzy]

I'm using ESP32 and more specific ESP-WROOM-32.

[jessebraham]

Your target should be xtensa-esp32-none-elf, as the ESP32 is Xtensa, not riscv32imc-uknown-none-elf.

[jptrzy]

I had it in the past set as a xtensa-esp32-none-elf, but I got the same error.

[jptrzy]

Now for some reason when I recreated the same steps on my laptop (that has the same OS and even its configuration) it just started magically working.

If someone like my has the same issue as my I would advise you to remove all the cache that cargo and rustup has.

I also use this nix flake.

flake.nix:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

    esp32 = {
      url = "github:knarkzel/esp32";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    esp-dev = {
      url = "github:mirrexagon/nixpkgs-esp-dev";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = {
    self,
    nixpkgs,
    esp32,
    esp-dev
  }: let
    pkgs = import nixpkgs {
      system = "x86_64-linux";
      overlays = [
        esp-dev.overlays.default
      ];
    };
    idf-rust = esp32.packages.x86_64-linux.esp32;
  in {
    devShells.x86_64-linux.default = pkgs.mkShell {
      buildInputs = [
        pkgs.esp-idf-esp32

        idf-rust
      ];

      shellHook = ''
        export PATH="${idf-rust}/.rustup/toolchains/esp/bin:$PATH"
        export RUST_SRC_PATH="$(rustc --print sysroot)/lib/rustlib/src/rust/src"
      '';
    };
  };
}