bump bootstrap compiler to 1.93 beta

[BoxyUwU]

r? release

[rustbot]

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

The Miri subtree was changed

cc @rust-lang/miri

[BoxyUwU]

r? mark-simulacrum

[Mark-Simulacrum]

@bors r+

[bors]

📌 Commit 8995537 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[matthiaskrgr]

@bors rollup=never

[jieyouxu]

@bors p=5 (just to get the bootstrap compiler bump done)

[bors]

⌛ Testing commit 8995537 with merge 7eae21d...

[bors]

💥 Test timed out

[Zalathar]

@bors retry (timeout)

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[cuviper]

@bors try jobs=i686-pc-windows-msvc

[cuviper]

@bors try jobs=i686-msvc-2

[rust-bors]

☀️ Try build successful (CI)
Build commit: 776cfb6 (776cfb6c723e584291c9845bcac062f8f865efeb, parent: fcf67da039f42e3905cf6f69e33304299c45149f)

[cuviper]

@bors r=Mark-Simulacrum,cuviper

[bors]

📌 Commit 575a02e has been approved by Mark-Simulacrum,cuviper

It is now in the queue for this repository.

[bors]

⌛ Testing commit 575a02e with merge 6b02110...

[rust-log-analyzer]

The job pr-check-2 failed! Check out the build log: (web) (plain enhanced) (plain)

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

Didn't find `Class::Original` to close
stack backtrace:
   0: __rustc::rust_begin_unwind
   1: core::panicking::panic_fmt
   2: rustdoc::html::highlight::end_expansion::<core::fmt::Formatter>
   3: rustdoc::html::highlight::write_code::<core::fmt::Formatter>::{closure#2}
   4: <rustdoc::html::highlight::Classifier>::advance
   5: rustdoc::html::highlight::classify
   6: rustdoc::html::highlight::write_code::<core::fmt::Formatter>
   7: <&core::fmt::builders::FromFn<rustdoc::html::sources::print_src<&mut core::fmt::Formatter>::{closure#0}> as core::fmt::Display>::fmt
   8: core::fmt::write
   9: <&askama::filters::escape::Safe<&core::fmt::builders::FromFn<rustdoc::html::sources::print_src<&mut core::fmt::Formatter>::{closure#0}>> as core::fmt::Display>::fmt
  10: core::fmt::write
  11: <rustdoc::html::sources::SourceCollector as rustdoc::visit::DocVisitor>::visit_item
  12: <rustdoc::html::sources::SourceCollector as rustdoc::visit::DocVisitor>::visit_item
  13: <rustdoc::html::sources::SourceCollector as rustdoc::visit::DocVisitor>::visit_item
  14: <rustdoc::html::render::context::Context>::init
---
warning: the ICE couldn't be written to `/checkout/rustc-ice-2025-12-19T04_36_53-185118.txt`: Read-only file system (os error 30)

note: rustc 1.93.0-beta.1 (1b6e21e16 2025-12-08) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib -Z unstable-options -C symbol-mangling-version=v0 -Z unstable-options -Z normalize-docs -Z crate-attr=warn(rust_2018_idioms) -Z force-unstable-if-unmarked -Z crate-attr=doc(rust_logo) -Z crate-attr=doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/") -Z crate-attr=feature(rustdoc_internals)

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
end of query stack
error: could not document `rustc_mir_build`
warning: build failed, waiting for other jobs to finish...
Command `/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo doc --target x86_64-unknown-linux-gnu -Zbinary-dep-depinfo -j 4 -Zroot-dir=/checkout --locked --color=always --release --features llvm --manifest-path /checkout/compiler/rustc/Cargo.toml -Zskip-rustdoc-fingerprint --no-deps -Zrustdoc-map -p rustc-main -p rustc_abi -p rustc_arena -p rustc_ast -p rustc_ast_ir -p rustc_ast_lowering -p rustc_ast_passes -p rustc_ast_pretty -p rustc_attr_parsing -p rustc_baked_icu_data -p rustc_borrowck -p rustc_builtin_macros -p rustc_codegen_llvm -p rustc_codegen_ssa -p rustc_const_eval -p rustc_data_structures -p rustc_driver -p rustc_driver_impl -p rustc_error_codes -p rustc_error_messages -p rustc_errors -p rustc_expand -p rustc_feature -p rustc_fluent_macro -p rustc_fs_util -p rustc_graphviz -p rustc_hashes -p rustc_hir -p rustc_hir_analysis -p rustc_hir_id -p rustc_hir_pretty -p rustc_hir_typeck -p rustc_incremental -p rustc_index -p rustc_index_macros -p rustc_infer -p rustc_interface -p rustc_lexer -p rustc_lint -p rustc_lint_defs -p rustc_llvm -p rustc_log -p rustc_macros -p rustc_metadata -p rustc_middle -p rustc_mir_build -p rustc_mir_dataflow -p rustc_mir_transform -p rustc_monomorphize -p rustc_next_trait_solver -p rustc_parse -p rustc_parse_format -p rustc_passes -p rustc_pattern_analysis -p rustc_privacy -p rustc_proc_macro -p rustc_public -p rustc_public_bridge -p rustc_query_impl -p rustc_query_system -p rustc_resolve -p rustc_sanitizers -p rustc_serialize -p rustc_session -p rustc_span -p rustc_symbol_mangling -p rustc_target -p rustc_thread_pool -p rustc_trait_selection -p rustc_traits -p rustc_transmute -p rustc_ty_utils -p rustc_type_ir -p rustc_type_ir_macros -p rustc_windows_rc [workdir=/checkout]` failed with exit code 101
Created at: src/bootstrap/src/core/build_steps/doc.rs:916:25
Executed at: src/bootstrap/src/core/build_steps/doc.rs:977:26

Command has failed. Rerun with -v to see more details.
Bootstrap failed while executing `doc compiler --stage 1`
Build completed unsuccessfully in 0:01:45
  local time: Fri Dec 19 04:37:00 UTC 2025
  network time: Fri, 19 Dec 2025 04:37:00 GMT
##[error]Process completed with exit code 1.

[bors]

💔 Test failed - checks-actions

[jieyouxu]

Huh, that looks like #148617 and #148655 🤔

[jieyouxu]

EDIT: also, I think there's like 4 cfg(bootstrap)/cfg(not(bootstrap)) in rustc_fluent_macros too, I'm seeing warnings for them locally?

[jieyouxu]

Ah. So, beta rustdoc currently is ICEing on in-tree rustc_mir_build likely due to #148617-adjacent reasons. It's possible to temporarily unblock this bootstrap bump by intentionally regressing the macro-expansion buttons in compiler docs via --generate-macro-expansion in doc::Rustc's

rust/src/bootstrap/src/core/build_steps/doc.rs

Line 935 in 526a91c

cargo.rustdocflag("--generate-macro-expansion");

$ git diff src/bootstrap/src/core/build_steps/doc.rs
diff --git a/src/bootstrap/src/core/build_steps/doc.rs b/src/bootstrap/src/core/build_steps/doc.rs
index fa36a6471ca..bf3de56cd02 100644
--- a/src/bootstrap/src/core/build_steps/doc.rs
+++ b/src/bootstrap/src/core/build_steps/doc.rs
@@ -932,7 +932,7 @@ fn run(self, builder: &Builder<'_>) {
         // see https://github.com/rust-lang/rust/pull/122066#issuecomment-1983049222
         // If there is any bug, please comment out the next line.
         cargo.rustdocflag("--generate-link-to-definition");
-        cargo.rustdocflag("--generate-macro-expansion");
+        //cargo.rustdocflag("--generate-macro-expansion");

         compile::rustc_cargo(builder, &mut cargo, target, &build_compiler, &self.crates);
         cargo.arg("-Zskip-rustdoc-fingerprint");

This locally makes ./x doc compiler/ --stage=1 pass for me. (Note that ./x doc compiler/ --stage=2 passes for me with an in-tree rustdoc, so it seems like only beta rustdoc is ICEing somehow.)

What I don't understand is why. Maybe #148655 wasn't sufficient, somehow? cc @GuillaumeGomez maybe you have any ideas?

EDIT: oh, this is very new:

• Generate macro expansion for rust compiler crates docs #150022
• [rustdoc] Fix invalid handling of field followed by negated macro call #150099

So yeah, we can temporarily revert enabling --generate-macro-expansion to unblock bootstrap bump.