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.

[GuillaumeGomez]

If the fix is included, this bug should be fixed. If it's an issue, please just comment this feature out for the time being.

Is there anything special about about we build compiler docs in this case? (so I can reproduce locally)

[jieyouxu]

Is there anything special about about we build compiler docs in this case? (so I can reproduce locally)

Not specifically that I know of (well, apart from the usual mix of unstable rustdoc flags too). If I'm not mistaken, the failing case is ./x doc compiler --stage=1 where we use a beta rustdoc to build in-tree compiler docs. Locally, I see that ./x doc compiler --stage=2 (in-tree rustdoc on in-tree compiler sources) passes and doesn't ICE.

There's several flags (including unstable ones) we build compiler docs with in

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

Line 925 in 07a5b02

cargo.rustdocflag("--document-private-items");

, some of which are not used for other parts of the codebase. I wonder if it's a convoluted combination of those that triggers an edge case...

EDIT: continuing this conversation over at #t-rustdoc > "Didn't find 'Class::Original' to close" since github is already folding comments. Let's try disabling the flag for now.