Also compile rustc_driver as rlib

[bjorn3]

This reduces the amount of patching necessary to get rustc working in environments where dynamic linking is not possible like wasm, miri or some niche OSes. There is still a single line patch necessary for miri to get the sysroot location (a future PR I have planned would as a side effect likely remove the need for this patch). For wasm some more intrusive patches are still necessary to disable thread usage.

We will still only ship it in rustc-dev as dylib (all rlibs are filtered) and given that it is an empty crate, it shouldn't have any noticable size or compile time impact on building rustc.

[rustbot]

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[rust-log-analyzer]

The job aarch64-gnu-llvm-20-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[PATCH] "stdlib" <- "0027-stdlib-128bit-atomic-operations.patch"
##[endgroup]
##[group][BUILD] mini_core
[BUILD] mini_core
error: couldn't load codegen backend /checkout/obj/build/aarch64-unknown-linux-gnu/stage2/lib/rustlib/aarch64-unknown-linux-gnu/codegen-backends/librustc_codegen_cranelift-1.93.0-nightly.so: /checkout/obj/build/aarch64-unknown-linux-gnu/stage2/lib/librustc_driver-abb419288f550991.so: cannot allocate memory in static TLS block

"/checkout/obj/build/aarch64-unknown-linux-gnu/stage2-codegen/cg_clif/dist/rustc-clif" "-Csymbol-mangling-version=v0" "-Zrandomize-layout" "-Zunstable-options" "--check-cfg=cfg(bootstrap)" "-Zmacro-backtrace" "-Csplit-debuginfo=off" "-Clink-arg=-L/usr/lib/llvm-20/lib" "-Cllvm-args=-import-instr-limit=10" "-Clink-args=-Wl,-z,origin" "-Clink-args=-Wl,-rpath,$ORIGIN/../lib" "-Alinker-messages" "-L" "crate=/checkout/obj/build/aarch64-unknown-linux-gnu/stage2-codegen/cg_clif/build/example" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2-codegen/cg_clif/build/example" "-Cdebuginfo=2" "--target" "aarch64-unknown-linux-gnu" "-Cpanic=abort" "--check-cfg=cfg(jit)" "example/mini_core.rs" "--crate-type" "lib,dylib" exited with status ExitStatus(unix_wait_status(256))
Bootstrap failed while executing `--stage 2 test --skip tests --skip coverage-map --skip coverage-run --skip library --skip tidyselftest`
Command `/checkout/obj/build/aarch64-unknown-linux-gnu/stage0/bin/cargo run --target aarch64-unknown-linux-gnu -Zbinary-dep-depinfo -j 4 -Zroot-dir=/checkout --locked --color always --release --manifest-path /checkout/compiler/rustc_codegen_cranelift/build_system/Cargo.toml -- test --download-dir /checkout/obj/build/cg_clif_download --out-dir /checkout/obj/build/aarch64-unknown-linux-gnu/stage2-codegen/cg_clif --no-unstable-features --use-backend cranelift --sysroot llvm --skip-test testsuite.extended_sysroot [workdir=/checkout/compiler/rustc_codegen_cranelift]` failed with exit code 1
Created at: src/bootstrap/src/core/build_steps/test.rs:3706:25
Executed at: src/bootstrap/src/core/build_steps/test.rs:3751:26

Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:20:35
  local time: Fri Nov  7 16:31:30 UTC 2025
  network time: Fri, 07 Nov 2025 16:31:30 GMT
##[error]Process completed with exit code 1.
##[group]Run echo "disk usage:"

[Kobzol]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[rust-log-analyzer]

The job dist-x86_64-linux failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

    Finished `dev` profile [unoptimized + debuginfo] target(s) in 32.44s
##[endgroup]
[2025-11-07T21:19:51.740Z INFO  opt_dist::timer] Section `Stage 1 (Rustc PGO)` starts
[2025-11-07T21:19:51.740Z INFO  opt_dist::timer] Section `Stage 1 (Rustc PGO) > Build PGO instrumented rustc and LLVM` starts
[2025-11-07T21:19:51.740Z INFO  opt_dist::exec] Executing `RUST_BACKTRACE=full python3 /checkout/x.py build --target x86_64-unknown-linux-gnu --host x86_64-unknown-linux-gnu --stage 2 library/std --set rust.llvm-bitcode-linker=false --set build.extended=false --set rust.codegen-backends=['llvm'] --set rust.deny-warnings=false --rust-profile-generate /tmp/tmp-multistage/opt-artifacts/rustc-pgo --set llvm.thin-lto=false --set llvm.link-shared=true [at /checkout/obj]`
##[group]Building bootstrap
    Finished `dev` profile [unoptimized] target(s) in 0.06s
##[endgroup]
[TIMING:start] compile::Assemble { target_compiler: Compiler { stage: 2, host: x86_64-unknown-linux-gnu, forced_compiler: false } }
[TIMING:start] builder::Libdir { compiler: Compiler { stage: 2, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu }
---
error: lto can only be run for executables, cdylibs and static library outputs

[RUSTC-TIMING] rustc_driver test:false 0.672
error: could not compile `rustc_driver` (lib) due to 1 previous error
Bootstrap failed while executing `build --target x86_64-unknown-linux-gnu --host x86_64-unknown-linux-gnu --stage 2 library/std --set rust.llvm-bitcode-linker=false --set build.extended=false --set rust.codegen-backends=['llvm'] --set rust.deny-warnings=false --rust-profile-generate /tmp/tmp-multistage/opt-artifacts/rustc-pgo --set llvm.thin-lto=false --set llvm.link-shared=true`
Build completed unsuccessfully in 0:13:49
[2025-11-07T21:33:41.171Z INFO  opt_dist::timer] Section `Stage 1 (Rustc PGO) > Build PGO instrumented rustc and LLVM` ended: FAIL (829.43s)`
[2025-11-07T21:33:41.171Z INFO  opt_dist::timer] Section `Stage 1 (Rustc PGO)` ended: FAIL (829.43s)`
[2025-11-07T21:33:41.171Z INFO  opt_dist] Timer results
    -----------------------------------------------------------------
---
[2025-11-07T21:33:41.172Z INFO  opt_dist::utils] Free disk space: 1.24 TiB out of total 2.18 TiB (43.11% used)
Error: Optimized build pipeline has failed

Caused by:
    Command RUST_BACKTRACE=full python3 /checkout/x.py build --target x86_64-unknown-linux-gnu --host x86_64-unknown-linux-gnu --stage 2 library/std --set rust.llvm-bitcode-linker=false --set build.extended=false --set rust.codegen-backends=['llvm'] --set rust.deny-warnings=false --rust-profile-generate /tmp/tmp-multistage/opt-artifacts/rustc-pgo --set llvm.thin-lto=false --set llvm.link-shared=true [at /checkout/obj] has failed with exit code Some(1)

Stack backtrace:
   0: <anyhow::Error>::msg::<alloc::string::String>
             at /rust/deps/anyhow-1.0.99/src/backtrace.rs:27:14
   1: <opt_dist::exec::CmdBuilder>::run
             at /rustc/f44cfc64a173c7f6cd19add8e362ff589b3d2220/src/tools/opt-dist/src/exec.rs:80:17
   2: <opt_dist::exec::Bootstrap>::run
             at /rustc/f44cfc64a173c7f6cd19add8e362ff589b3d2220/src/tools/opt-dist/src/exec.rs:199:18
   3: opt_dist::execute_pipeline::{closure#1}::{closure#0}
             at /rustc/f44cfc64a173c7f6cd19add8e362ff589b3d2220/src/tools/opt-dist/src/main.rs:256:21
   4: <opt_dist::timer::TimerSection>::section::<opt_dist::execute_pipeline::{closure#1}::{closure#0}, ()>
             at /rustc/f44cfc64a173c7f6cd19add8e362ff589b3d2220/src/tools/opt-dist/src/timer.rs:111:22
   5: opt_dist::execute_pipeline::{closure#1}
             at /rustc/f44cfc64a173c7f6cd19add8e362ff589b3d2220/src/tools/opt-dist/src/main.rs:245:15
   6: <opt_dist::timer::TimerSection>::section::<opt_dist::execute_pipeline::{closure#1}, opt_dist::training::RustcPGOProfile>
             at /rustc/f44cfc64a173c7f6cd19add8e362ff589b3d2220/src/tools/opt-dist/src/timer.rs:111:22
   7: opt_dist::execute_pipeline
             at /rustc/f44cfc64a173c7f6cd19add8e362ff589b3d2220/src/tools/opt-dist/src/main.rs:242:35
   8: opt_dist::main
             at /rustc/f44cfc64a173c7f6cd19add8e362ff589b3d2220/src/tools/opt-dist/src/main.rs:467:18
   9: <fn() -> core::result::Result<(), anyhow::Error> as core::ops::function::FnOnce<()>>::call_once
             at /rustc/3b4dd9bf1410f8da6329baa36ce5e37673cbbd1f/library/core/src/ops/function.rs:250:5
  10: std::sys::backtrace::__rust_begin_short_backtrace::<fn() -> core::result::Result<(), anyhow::Error>, core::result::Result<(), anyhow::Error>>
             at /rustc/3b4dd9bf1410f8da6329baa36ce5e37673cbbd1f/library/std/src/sys/backtrace.rs:158:18
  11: std::rt::lang_start::<core::result::Result<(), anyhow::Error>>::{closure#0}
             at /rustc/3b4dd9bf1410f8da6329baa36ce5e37673cbbd1f/library/std/src/rt.rs:206:18
  12: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once
             at /rustc/3b4dd9bf1410f8da6329baa36ce5e37673cbbd1f/library/core/src/ops/function.rs:287:21
  13: std::panicking::catch_unwind::do_call
             at /rustc/3b4dd9bf1410f8da6329baa36ce5e37673cbbd1f/library/std/src/panicking.rs:590:40
  14: std::panicking::catch_unwind
             at /rustc/3b4dd9bf1410f8da6329baa36ce5e37673cbbd1f/library/std/src/panicking.rs:553:19

[rust-bors]

💔 Test for f44cfc6 failed: CI. Failed jobs:

• try - dist-x86_64-linux (web logs, extended logs)