Cargo build failes due to errors

[sykacek]

First, I had to edit line 7 in avr-atmega328p.json to

    "os": "none",

Without the change, build process stops immediately. But cargo build still produces the following error:

Compiling avr-device v0.2.1
warning: target json file contains unused fields: target-env, target-vendor

error: cannot find macro `llvm_asm` in this scope
 --> /home/mike/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/avr-device-0.2.1/src/asm.rs:6:14
  |
6 |     unsafe { llvm_asm!("nop") }
  |              ^^^^^^^^

error: cannot find macro `llvm_asm` in this scope
  --> /home/mike/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/avr-device-0.2.1/src/asm.rs:12:14
   |
12 |     unsafe { llvm_asm!("sleep") }
   |              ^^^^^^^^

error: cannot find macro `llvm_asm` in this scope
  --> /home/mike/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/avr-device-0.2.1/src/asm.rs:18:14
   |
18 |     unsafe { llvm_asm!("wdr") }
   |              ^^^^^^^^

error: cannot find macro `llvm_asm` in this scope
  --> /home/mike/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/avr-device-0.2.1/src/interrupt.rs:17:9
   |
17 |         llvm_asm!(
   |         ^^^^^^^^

error: cannot find macro `llvm_asm` in this scope
  --> /home/mike/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/avr-device-0.2.1/src/interrupt.rs:30:5
   |
30 |     llvm_asm!(
   |     ^^^^^^^^

error: cannot find macro `llvm_asm` in this scope
  --> /home/mike/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/avr-device-0.2.1/src/interrupt.rs:46:9
   |
46 |         llvm_asm!(
   |         ^^^^^^^^

error[E0635]: unknown feature `llvm_asm`
  --> /home/mike/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/avr-device-0.2.1/src/lib.rs:23:12
   |
23 | #![feature(llvm_asm)]
   |            ^^^^^^^^

For more information about this error, try `rustc --explain E0635`.
warning: `avr-device` (lib) generated 1 warning
error: could not compile `avr-device` (lib) due to 7 previous errors; 1 warning emitted

Output of rustup show

Default host: x86_64-unknown-linux-gnu
rustup home:  /home/mike/.rustup

installed toolchains
--------------------

stable-x86_64-unknown-linux-gnu
nightly-2024-03-22-x86_64-unknown-linux-gnu
nightly-x86_64-unknown-linux-gnu (default)

active toolchain
----------------

nightly-x86_64-unknown-linux-gnu (default)
rustc 1.87.0-nightly (96cfc7558 2025-02-27)

How can I fix it?