LLVM download size

[allsey87]

I would like to compile Rust code to wasm32-wasip1 in Bazel and have the following configuration in my MODULE.bazel. What is a little bit annoying though is the massive download (1-2 GB) and extraction process which takes quite some time to complete. This seems excessive considering the LLVM version bundled with the Emscripten SDK, for example, is only around 200 MB. Am I doing something wrong here?

module(name = "workspace")

bazel_dep(name = "platforms", version = "0.0.11")
bazel_dep(name = "rules_rust", version = "0.61.0")
bazel_dep(name = "toolchains_llvm", version = "1.4.0", dev_dependency = True)

http_archive = use_repo_rule("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
wasi_sdk_sysroots = use_repo_rule("//:wasi_sdk.bzl", "wasi_sdk_sysroots")
libclang_rt_wasm32 = use_repo_rule("//:wasi_sdk.bzl", "libclang_rt_wasm32")

wasi_sdk_sysroots(name = "wasi_sdk_sysroots")
libclang_rt_wasm32(name = "libclang_rt_wasm32")

llvm = use_extension("@toolchains_llvm//toolchain/extensions:llvm.bzl", "llvm", dev_dependency = True)
llvm.toolchain(
    name = "llvm_toolchain_wasm_wasi",
    libclang_rt = {
        "@libclang_rt_wasm32//:libclang_rt.builtins-wasm32.a":
            "wasm32-unknown-wasip1/libclang_rt.builtins.a",
    },
    llvm_versions = {
        "": "20.1.1",
    },
    stdlib = {
        "wasip1-wasm32": "libc",
    },
)
llvm.sysroot(
    name = "llvm_toolchain_wasm_wasi",
    label = "@wasi_sdk_sysroots//wasm32-wasip1",
    targets = ["wasip1-wasm32"],
)
use_repo(llvm, "llvm_toolchain_wasm_wasi")

register_toolchains("@llvm_toolchain_wasm_wasi//:all", dev_dependency = True)

rust = use_extension("@rules_rust//rust:extensions.bzl", "rust")
rust.toolchain(
    edition = "2021",
    extra_target_triples = ["wasm32-wasip1"],
    versions = ["1.87.0"],
    sha256s = {
        "rustc-1.87.0-x86_64-unknown-linux-gnu.tar.xz": "e8395c5c5756253b76107055e093ffbc4431af7b30aeebe72ce2684b9cb53973",
        "clippy-1.87.0-x86_64-unknown-linux-gnu.tar.xz": "9d440eef6811112a000acf96a062df7bcbc013fa4f8e00a7f9a4f57ef90637a1",
        "cargo-1.87.0-x86_64-unknown-linux-gnu.tar.xz": "469d5dc479835adadd728bc3587f8abf1941b3dd71f9865abd3e0783ae662555",
        "llvm-tools-1.87.0-x86_64-unknown-linux-gnu.tar.xz": "872fdd4b3b8f6bcb01d20aae02cdd7848472386c9ba54c641d63ff82246ae935",
        "rust-std-1.87.0-x86_64-unknown-linux-gnu.tar.xz": "1b57253bd32b8b292c965b3a2d992a266763158494cab8555584c09360b90f77"
    },
)
use_repo(rust, "rust_toolchains")
register_toolchains("@rust_toolchains//:all")