fs::read_to_string(config.src.join("src/ci/channel")) failed with No such file or directory (os error 2) about rust HOT 4 OPEN

  ~/downloads/rustc-1.80.0-src  $ ./x.py build --dry-run
Building bootstrap
   Compiling bootstrap v0.0.0 (/home/nimda/downloads/rustc-1.80.0-src/src/bootstrap)
    Finished `dev` profile [unoptimized] target(s) in 3.31s
[src/core/config/config.rs:1319:9] config.src.join("src/ci/channel") = "/home/nimda/downloads/rustc-1.80.0-src/src/ci/channel"
WARNING: you have not made a `config.toml`
HELP: consider running `./x.py setup` or copying `config.example.toml` by running `cp config.example.toml config.toml`
Building stage0 library artifacts (x86_64-unknown-linux-gnu)
Building LLVM for x86_64-unknown-linux-gnu
Building compiler artifacts (stage0 -> stage1, x86_64-unknown-linux-gnu)
Creating a sysroot for stage1 compiler (use `rustup toolchain link 'name' build/host/stage1`)
Building stage1 library artifacts (x86_64-unknown-linux-gnu)
WARNING: no codegen-backends config matched the requested path to build a codegen backend. HELP: add backend to codegen-backends in config.toml.
Building tool rustdoc (stage0 -> stage1, x86_64-unknown-linux-gnu)
WARNING: you have not made a `config.toml`
HELP: consider running `./x.py setup` or copying `config.example.toml` by running `cp config.example.toml config.toml`
NOTE: this message was printed twice to make it more likely to be seen
Build completed successfully in 0:00:03