config.toml

# This is for making a Rust toolchain that is useful for building crates such that they link to
# std libs that are better for debugger'ing the std libs themselves because these from this
# toolchain have more debug-info, less optimizations, and file+line info referring to the files in
# the rust-lang/rust.git repo checkout that this toolchain is made from which helps rust-analyzer
# (along with my extra ./.dir-locals.el for my Emacs support) better understand and navigate the
# std libs source code.

# Remember: Have these env vars for the `./x build && ./x install`, etc commands:
#             RUSTFLAGS="-C target-cpu=native"
#             RUSTFLAGS_BOOTSTRAP="-C opt-level=3 -C debuginfo=0"
#             RUSTFLAGS_NOT_BOOTSTRAP="-Z tune-cpu=native -C inline-threshold=0"
#           Which ./shell.nix sets up.

change-id = 121754  # This will need to be updated in the future.

[llvm]
download-ci-llvm = false  # Want to use the host's libLLVM, instead.
link-shared = true  # Needed to use the NixOS host's libLLVM. (The .a LLVM libs don't work.)

[build]
# verbose = 1
# extended = true  # Also build the tools (e.g. cargo, clippy, rust-analyzer, etc.).
# tools = [
#    "cargo",
#  # "clippy",
#  # "rustfmt",
#    "rust-analyzer",
#    "rust-analyzer-proc-macro-srv",
#  # "src",
# ]
low-priority = true  # "Nice" +10.
docs = false  # Faster total build without these.
# build-dir = "/var/tmp/home/z/rust-lang/build"

[rust]
download-rustc = false  # This is the default. Just to be explicit that we want to build it.
channel = "stable"  # Build a "stable"-channel Rust (i.e. that can't use unstable features).
debug = true  # Build as debug mode, for using debugger to explore the std libs.
frame-pointers = true  # Might help fidelity of debugging.
optimize = false  # No optimizations, to help fidelity of debugging.
optimize-tests = false  # Might as well.
debug-assertions = false  # Not worried about correctness of compiler, nor std libs, nor tools.
overflow-checks = false   # Ditto.
debug-logging = false  # Don't care about traces.
debuginfo-level = 0  # Don't care about debug info for compiler nor tools.
debuginfo-level-std = 2  # Full debug info with variable and type information, only for std libs.
incremental = false  # Faster initial build. (I don't plan to make changes.)
lto = "off"  # Faster to build, at the expense of a ~20% runtime slowdown.
dist-src = false  # Don't need this.

[target.x86_64-unknown-linux-gnu]
# To use the host system's LLVM (instead of building it) (will need to be updated in the future):
llvm-config = "/nix/store/2pwhs3dl0vy7nw0lqyx9s5d53h1vi0y9-llvm-18.1.4-dev/bin/llvm-config"

[install]
prefix = "/home/z/.rustup/toolchains/my-debug-std"
sysconfdir = "etc"