feat(report): new command `cargo report sessions` #16428

weihanglo · 2025-12-23T14:53:44Z

What does this PR try to resolve?

A new report command cargo report sessions is added.
The motivation of this is to provide an access to the build session ID,
so that user can retrieve reports for specific session.
For example, cargo report timings --id <my-older-build>.

The command name sessions was chosen because

It is a thing that Cargo "reports to user",
feeling more reasonable than cargo report list-runs
or cargo rebuild recent-builds.
Discussed with @Muscraft,
and we feel SessionId will be a better term in RunId.
While whether a cargo invocation is a session is debatable,
sessions the term is widely used for logging and metrics.
This is unstable. We can always change its name later.

Design decision:

Doesn't show total number of sessions to not be a performance burden when we add filtering, see feat(report): new command cargo report sessions #16428 (comment)

Part of #15844

Fixes #16401

How to test and review this PR?

See tests for the report output.
It is a simple text-based report. JSON schema is not included.

$ cargo report sessions -Zbuild-analysis
Session IDs for `/projects/cargo` (most recent first):

 - 20251218T220836847Z-0e981be2243ad433
 - 20251218T220801494Z-0e981be2243ad433
 - 20251218T220704295Z-0e981be2243ad433
 
... and more (use --limit N to see more)

Unresolved questions

without a workspace, do we error? if not, should we have a flag for forcing of global listing? (feat(report): new command cargo report sessions #16428 (comment), feat(report): new command cargo report sessions #16428 (comment))

rustbot · 2025-12-23T14:53:49Z

r? @ehuss

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tests/testsuite/cargo_report_sessions/mod.rs

tests/testsuite/cargo_report_sessions/help/stdout.term.svg

epage · 2025-12-26T13:16:24Z

tests/testsuite/cargo_report_sessions/help/stdout.term.svg

Should there be a flag to force global search? This can be deferred to the tracking issue.

Yeah, worth considering. I've thought of that. I am mostly following the currently behavior of cargo report timings. When stabilizing they should have a similar behavior anyway.

epage · 2025-12-26T13:16:44Z

tests/testsuite/cargo_report_sessions/help/stdout.term.svg

Should global search be implicit or should we error? This can be deferred to the tracking issue.

#16428 (comment)

Thanks. Will track it!

src/bin/cargo/commands/report.rs

### What does this PR try to resolve? Spin off from <#16428 (comment)>. ### How to test and review this PR?

epage · 2025-12-29T19:38:34Z

src/cargo/ops/cargo_report/sessions.rs

+            ws.root().display(),
+        )?;
+    } else {
+        writeln!(stderr, "Session IDs (most recent irst):",)?


irst -> first

epage

Feel free to merge when the typo is fixed

View changes since this review

So that it can be used elsewhere we need to list log files.

A new report command `cargo report sessions` is added. The motivation of this is to provide an access to the build session ID, so that user can retrieve reports for specific session. For example, `cargo report timings --id <my-older-build>`. The command name `sessions` was chosen because * It is a thing that Cargo "reports to user", feeling more reasonable than `cargo report list-runs` or `cargo rebuild recent-builds`. * Discussed with `@Muscraft`, and we feel `SessionId` will be a better term in `RunId`. While whether a `cargo` invocation is a session is debatable, sessions the term is widely used for logging and metrics. * This is unstable. We can always change its name later. Part of rust-lang#15844

rustbot · 2025-12-29T20:00:41Z

This PR was rebased onto a different master 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.

Update cargo submodule 9 commits in 94c368ad2b9db0f0da5bdd8421cea13786ce4412..b54051b1505281ec7a45a250140a0ff25d33f319 2025-12-26 19:39:15 +0000 to 2025-12-30 20:35:52 +0000 - 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) r? ghost

Update cargo submodule 19 commits in 94c368ad2b9db0f0da5bdd8421cea13786ce4412..623444427f04292f3a3c7eac560cfa65ba0bb88e 2025-12-26 19:39:15 +0000 to 2026-01-06 21:05:05 +0000 - 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) r? ghost

Update cargo submodule 24 commits in 94c368ad2b9db0f0da5bdd8421cea13786ce4412..fc4c92b64d1e0046b66cbdc747cc1c17af8b35a0 2025-12-26 19:39:15 +0000 to 2026-01-08 06:54:56 +0000 - 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)

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)

weihanglo added Command-report Z-build-analysis Nightly: build-analysis labels Dec 23, 2025

rustbot assigned ehuss Dec 23, 2025

rustbot added A-cli Area: Command-line interface, option parsing, etc. S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Dec 23, 2025

weihanglo force-pushed the report-sessions branch from e6d2a88 to f54a22a Compare December 23, 2025 15:14

weihanglo changed the title ~~refactor(report): make log file select more generic~~ feat(report): new command cargo report sessions Dec 23, 2025

weihanglo changed the title ~~feat(report): new command cargo report sessions~~ feat(report): new command cargo report sessions Dec 23, 2025

weihanglo mentioned this pull request Dec 26, 2025

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

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weihanglo force-pushed the report-sessions branch from f54a22a to dafcdb3 Compare December 26, 2025 13:06

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