fix(timing)!: remove `--timings=<FMT>` optional format values by weihanglo · Pull Request #16420 · rust-lang/cargo

weihanglo · 2025-12-19T20:18:06Z

What does this PR try to resolve?

Arguments to remove it

The --timings=json is obsolete as -Zbuild-analysis logging is
a more approachable option, which doesn't need passing
--timings=json ahead of time.
There is no support infra built around --timings=json yet,
while for -Zbuild-analysis we have cargo report timings already.
--timings=json is a UI feature inherently unstable, and has no tests.

Counterargument:

--timings=json outputs to stdout, but there is no alternative yet
also outputs to stdout.
feat(log): add output control #16418 was an attempt to add that back,
but we then decide to punt until seeing requests or needs.

How to test and review this PR?

cargo help build and check the manpage
cargo build --help and cehck the help text
cargo build --timings and it works

rustbot · 2025-12-19T20:18:11Z

r? @ehuss

rustbot has assigned @ehuss.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

weihanglo · 2025-12-19T20:19:42Z

Does it require an FCP?

Might be good to get a vibe check in case there is interest in build analysis having X amount of functionality before it can replace --timings=json

This has entered FCP: #16420 (comment).

I personally don't think we need to wait for the extra 10 days.

People may not notice the removal until at least it hits nightly.

People care about the evolution of timing report may have already followed the goal update in https://blog.rust-lang.org/2026/01/05/project-goals-2025-december-update/

This is a nightly feature.

I am fine if we still want to wait for the full FCP.

Arguments to remove it * The `--timings=json` is obsolete as `-Zbuild-analysis` logging is a more approachable option, which doesn't need passing `--timings=json` ahead of time. * There is no support infra built around `--timings=json` yet, while for `-Zbuild-analysis` we have `cargo report timings` already. * `--timings=json` is a UI feature inherently unstable, and has no tests. Counterargument: * `--timings=json` outputs to stdout, but there is no alternative yet also outputs to stdout.

weihanglo · 2025-12-19T20:28:13Z

@rfcbot fcp merge T-cargo

This removes support for --timings=json, making --timings a plain boolean flag after JSON timing output was removed. See the PR descriptions for more.

rust-rfcbot · 2025-12-19T20:28:16Z

Team member @weihanglo has proposed to merge this. The next step is review by the rest of the tagged team members:

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

rust-rfcbot · 2026-01-06T22:17:49Z

🔔 This is now entering its final comment period, as per the review above. 🔔

Update cargo submodule 27 commits in 94c368ad2b9db0f0da5bdd8421cea13786ce4412..8c133afcd5e0d69932fe11f5907683723f8d361d 2025-12-26 19:39:15 +0000 to 2026-01-09 03:50:15 +0000 - Isolate build script metadata progation between std and non-std crates (rust-lang/cargo#16489) - Add Clippy like lint groups (rust-lang/cargo#16464) - feat: in-memory only `Manifest` (rust-lang/cargo#16409) - Fixed incorrect version comparision during build script dependency selection (rust-lang/cargo#16486) - refactor: new type for unit index (rust-lang/cargo#16485) - feat(test): Make CARGO_BIN_EXE_ available at runtime (rust-lang/cargo#16421) - fix(package): detect dirty files when run from workspace member (rust-lang/cargo#16479) - fix(timing)!: remove `--timings=<FMT>` optional format values (rust-lang/cargo#16420) - docs(unstable): expand docs for `-Zbuild-analysis` (rust-lang/cargo#16476) - test: add `-Zunstable-options` with custom targets (rust-lang/cargo#16467) - feat(report): add cargo report rebuilds (rust-lang/cargo#16456) - feat(test-support): Use test name for dir when running tests (rust-lang/cargo#16121) - refactor: Migrate some cases to expect/reason (rust-lang/cargo#16461) - docs(build-script): clarify OUT_DIR is not cleaned between builds (rust-lang/cargo#16437) - chore: Update dependencies (rust-lang/cargo#16460) - Update handlebars to 6.4.0 (rust-lang/cargo#16457) - chore(deps): update alpine docker tag to v3.23 (rust-lang/cargo#16454) - Any build scripts can now use cargo::metadata=KEY=VALUE (rust-lang/cargo#16436) - fix(log): add `dependencies` field to `UnitRegistered` (rust-lang/cargo#16448) - Implement fine grain locking for `build-dir` (rust-lang/cargo#16155) - feat(resolver): List features when no close match (rust-lang/cargo#16445) - feat(report): new command `cargo report sessions` (rust-lang/cargo#16428) - feat (patch): Display where the patch was defined in patch-related error messages (rust-lang/cargo#16407) - test(build-rs): Reduce from 'build' to 'check' where possible (rust-lang/cargo#16444) - feat(toml): TOML 1.1 parse support (rust-lang/cargo#16415) - feat(report): support --manifest-path in `cargo report timings` (rust-lang/cargo#16441) - fix(vendor): recursively filter git files in subdirectories (rust-lang/cargo#16439)

This commit updates rust to a nightly release of rust, dated 1 day post 1.93.1. This version, as it is nightly, includes nightly features from rust v1.94, which includes the optional file format for the `--timings` report. ref: rust-lang/cargo#16420

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420). Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors in DataType enum by replacing Box<DataType> with Box<Self> in variant definitions Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors in DataType enum by replacing Box<DataType> with Box<Self> in variant definitions Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420). Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors by replacing self-referential type names with Self in DataType, ArrowSchema, ArrowArray, ArrowArrayStream, Literal, and Error enum/struct definitions - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Allow clippy::only_used_in_recursion on HuggingFace request method - Fix useless_vec lint in daft-io test Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors by replacing self-referential type names with Self in DataType, ArrowSchema, ArrowArray, ArrowArrayStream, Literal, and Error enum/struct definitions - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Allow clippy::only_used_in_recursion on HuggingFace request method - Fix useless_vec lint in daft-io test Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors by replacing self-referential type names with Self in DataType, ArrowSchema, ArrowArray, ArrowArrayStream, Literal, and Error enum/struct definitions - Allow clippy::use_self on Error::CachedError variant (snafu derive macro generates code with concrete type names, incompatible with Self) - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Allow clippy::only_used_in_recursion on HuggingFace request method - Fix useless_vec lint in daft-io test Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors by replacing self-referential type names with Self in DataType, ArrowSchema, ArrowArray, ArrowArrayStream, Literal, FakeSchema, FakeArray, and Error enum/struct definitions - Allow clippy::use_self on Error::CachedError variant (snafu derive macro generates code with concrete type names, incompatible with Self) - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Allow clippy::self_only_used_in_recursion on HuggingFace request method (lint renamed from only_used_in_recursion in newer clippy) - Fix useless_vec lint in daft-io test Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors by replacing self-referential type names with Self in DataType, ArrowSchema, ArrowArray, ArrowArrayStream, Literal, FakeSchema, FakeArray, and Error enum/struct definitions - Allow clippy::use_self on Error::CachedError variant (snafu derive macro generates code with concrete type names, incompatible with Self) - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Allow clippy::self_only_used_in_recursion on HuggingFace request method (lint renamed from only_used_in_recursion in newer clippy) - Fix useless_vec lint in daft-io test - Fix derivable_impls lint on PreviewFormat by using #[derive(Default)] Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors by replacing self-referential type names with Self in DataType, ArrowSchema, ArrowArray, ArrowArrayStream, Literal, FakeSchema, FakeArray, Value, and Error enum/struct definitions - Allow clippy::use_self on snafu-derived Error variants that use Arc<Error> (snafu macro generates code with concrete type names, incompatible with Self): daft-io CachedError, daft-parquet RemoteFetchFailed - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Allow clippy::self_only_used_in_recursion on HuggingFace request method (lint renamed from only_used_in_recursion in newer clippy) - Fix useless_vec lint in daft-io test - Fix derivable_impls lint on PreviewFormat by using #[derive(Default)] Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors by replacing self-referential type names with Self in DataType, ArrowSchema, ArrowArray, ArrowArrayStream, Literal, FakeSchema, FakeArray, Value, PlanJsonConfig, and Error enum/struct definitions - Allow clippy::use_self on snafu-derived Error variants that use Arc<Error> (snafu macro generates code with concrete type names, incompatible with Self): daft-io CachedError, daft-parquet RemoteFetchFailed - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Allow clippy::self_only_used_in_recursion on HuggingFace request method (lint renamed from only_used_in_recursion in newer clippy) - Fix useless_vec lint in daft-io test - Fix derivable_impls lint on PreviewFormat by using #[derive(Default)] Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility - Fix clippy use_self lint errors by replacing self-referential type names with Self in DataType, ArrowSchema, ArrowArray, ArrowArrayStream, Literal, FakeSchema, FakeArray, Value, PlanJsonConfig, JoinOrderTree, and Error enum/struct definitions - Allow clippy::use_self on snafu-derived Error variants that use Arc<Error> (snafu macro generates code with concrete type names, incompatible with Self): daft-io CachedError, daft-parquet RemoteFetchFailed - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Rename clippy::only_used_in_recursion allow attributes to clippy::self_only_used_in_recursion (lint renamed in newer clippy) - Fix ref_as_ptr lint in daft-recordbatch test by using std::ptr::from_ref - Fix useless_vec lint in daft-io test - Fix derivable_impls lint on PreviewFormat by using #[derive(Default)] Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bump rust nightly toolchain from nightly-2025-09-03 to nightly-2026-01-08. This picks up the ArrayChunks::into_remainder() return type change (rust-lang/rust#149127) while staying before the cargo --timings=html removal (rust-lang/cargo#16420), which CI still relies on. Changes to accommodate the new nightly: - Fix into_remainder() call in daft-minhash to match new return type (no longer wrapped in Option) (This enables distributions to build with Rust 1.93 stable and newer when RUSTC_BOOTSTRAP is set.) - Upgrade cargo-llvm-cov from 0.7.1 to 0.8.7 to fix corrupt profraw files due to LLVM profdata format incompatibility Clippy lint fixes for newer nightly: - Fix use_self by replacing self-referential type names with Self across multiple enum/struct definitions - Allow clippy::use_self on snafu-derived Error variants that use Arc<Error> (snafu macro generates code with concrete type names, incompatible with Self): daft-io CachedError, daft-parquet RemoteFetchFailed - Allow clippy::result_large_err in daft-io/src/tos.rs (IO error types are inherently large) - Rename clippy::only_used_in_recursion allow attributes to clippy::self_only_used_in_recursion (lint renamed in newer clippy) - Fix ref_as_ptr by using std::ptr::from_ref - Fix unnecessary_unwrap in daft-sql by using if-let - Fix unchecked_time_subtraction by using checked_sub().unwrap() - Fix useless_vec in daft-io test - Fix derivable_impls on PreviewFormat by using #[derive(Default)] Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

rustbot assigned ehuss Dec 19, 2025

weihanglo commented Dec 19, 2025

View reviewed changes

weihanglo added the T-cargo Team: Cargo label Dec 19, 2025

weihanglo force-pushed the timing branch from acc1b50 to f851173 Compare December 19, 2025 20:27

This comment was marked as outdated.

Sign in to view

rust-rfcbot added proposed-final-comment-period An FCP proposal has started, but not yet signed off. disposition-merge FCP with intent to merge labels Dec 19, 2025

weihanglo mentioned this pull request Dec 26, 2025

Prototype Cargo build analysis rust-lang/rust-project-goals#398

Closed

4 tasks

weihanglo mentioned this pull request Jan 5, 2026

feat(report): add cargo report rebuilds #16456

Merged

ehuss added this to Cargo status tracker Jan 6, 2026

ehuss moved this to FCP merge in Cargo status tracker Jan 6, 2026

weihanglo mentioned this pull request Jan 6, 2026

Reuse timing metric collection logic between --timings and -Zbuild-analysis #16474

Closed

rust-rfcbot added the final-comment-period FCP — a period for last comments before action is taken label Jan 6, 2026

rust-rfcbot removed the proposed-final-comment-period An FCP proposal has started, but not yet signed off. label Jan 6, 2026

epage approved these changes Jan 7, 2026

View reviewed changes

epage added this pull request to the merge queue Jan 7, 2026

rustbot added this to the 1.94.0 milestone Jan 9, 2026

weihanglo deleted the timing branch January 12, 2026 01:23

rust-rfcbot added finished-final-comment-period FCP complete to-announce and removed final-comment-period FCP — a period for last comments before action is taken labels Jan 16, 2026

Mark-Simulacrum mentioned this pull request Jan 25, 2026

Draft release notes for 1.94.0 rust-lang/rust#151650

Closed

Javagedes mentioned this pull request Mar 5, 2026

Update rust to v1.93.1 OpenDevicePartnership/patina-devops#89

Merged

smklein mentioned this pull request Mar 13, 2026

[rust-toolchain] bump to 1.94.0 oxidecomputer/omicron#10058

Merged

mikedep333 mentioned this pull request May 26, 2026

fix: update code for nightly-2026-01-08 toolchain Eventual-Inc/Daft#6982

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

fix(timing)!: remove `--timings=<FMT>` optional format values#16420

fix(timing)!: remove `--timings=<FMT>` optional format values#16420
epage merged 1 commit into
rust-lang:masterfrom
weihanglo:timing

weihanglo commented Dec 19, 2025 •

edited

Loading

Uh oh!

rustbot commented Dec 19, 2025

Uh oh!

weihanglo Dec 19, 2025

Uh oh!

epage Dec 19, 2025

Uh oh!

weihanglo Jan 7, 2026

Uh oh!

This comment was marked as outdated.

This comment was marked as outdated.

weihanglo commented Dec 19, 2025

Uh oh!

rust-rfcbot commented Dec 19, 2025 •

edited by Muscraft

Loading

Uh oh!

rust-rfcbot commented Jan 6, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

Conversation

weihanglo commented Dec 19, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

What does this PR try to resolve?

How to test and review this PR?

Uh oh!

rustbot commented Dec 19, 2025

Uh oh!

weihanglo Dec 19, 2025

Choose a reason for hiding this comment

Uh oh!

epage Dec 19, 2025

Choose a reason for hiding this comment

Uh oh!

weihanglo Jan 7, 2026

Choose a reason for hiding this comment

Uh oh!

This comment was marked as outdated.

This comment was marked as outdated.

weihanglo commented Dec 19, 2025

Uh oh!

rust-rfcbot commented Dec 19, 2025 • edited by Muscraft Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

rust-rfcbot commented Jan 6, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

weihanglo commented Dec 19, 2025 •

edited

Loading

rust-rfcbot commented Dec 19, 2025 •

edited by Muscraft

Loading