regression: cannot find type SourceFile in crate proc_macro

[BoxyUwU]

• https://crater-reports.s3.amazonaws.com/beta-rustdoc-1.91-2/beta-2025-09-21/reg/crazyflie-link-0.3.0/log.txt

[INFO] [stdout] error[E0412]: cannot find type `SourceFile` in crate `proc_macro`
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.85/src/wrapper.rs:365:26
[INFO] [stdout]     |
[INFO] [stdout] 365 |     Compiler(proc_macro::SourceFile),
[INFO] [stdout]     |                          ^^^^^^^^^^ not found in `proc_macro`
[INFO] [stdout]     |
[INFO] [stdout] help: consider importing one of these structs

[madsmtm]

Fixed in newer version of proc-macro2, unsure why the old version is picked here?

[Skgland]

Fixed in newer version of proc-macro2, unsure why the old version is picked here?

[INFO] crate crates.io crate crazyflie-link 0.3.0 already has a lockfile, it will not be regenerated

And the lockfile contains proc-macro2@1.0.85¹

Footnotes

1. https://docs.rs/crate/crazyflie-link/0.3.0/source/Cargo.lock#552 ↩

[cuviper]

I don't understand how this is a new regression either, when that type was removed in 1.88: 3962069

Some failure of (old) proc-macro2's feature detection?

[Skgland]

Looks like crazyflie-link@0.3.0 passed the normal (non rustdoc) crater runs 1.89 and 1.90 and 1.91.
For 1.88 it failed due to running out of disk space and the crater run wasn't retried.

For the 1.88 and 1.89 rustdoc crater runs it again ran out of diskspace and the runs weren't retried.
For 1.90 rustdoc crater run it ended up as build-fail as both the 1.89.0 (this I find surprising) and the beta build failed¹²
For 1.91 for some reason crazyflie-link@0.3.0 when compiled with rustdoc 1.90³ succeeded but failed when compiled with beta rustdoc⁴.

Footnotes

1. https://crater-reports.s3.amazonaws.com/beta-rustdoc-1.90-2/1.89.0/reg/crazyflie-link-0.3.0/log.txt ↩

2. https://crater-reports.s3.amazonaws.com/beta-rustdoc-1.90-2/beta-2025-08-22/reg/crazyflie-link-0.3.0/log.txt ↩

3. https://crater-reports.s3.amazonaws.com/beta-rustdoc-1.91-2/1.90.0/reg/crazyflie-link-0.3.0/log.txt ↩

4. https://crater-reports.s3.amazonaws.com/beta-rustdoc-1.91-2/beta-2025-09-21/reg/crazyflie-link-0.3.0/log.txt ↩

[theemathas]

The same failure in other crates from the previous crater run: #142428

[cuviper]

For 1.91 for some reason crazyflie-link@0.3.0 when compiled with rustdoc 1.903 succeeded but failed when compiled with beta rustdoc4.

They both succeeded on the first part, but only the latter tried (and failed) this command:

[INFO] running Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "RUSTC_BOOTSTRAP=1" "-e" "DOCS_RS=1" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "rustdoc" "--lib" "-Zrustdoc-map" "--config" "build.rustdocflags=[\"--cfg\", \"docsrs\", \"-Z\", \"unstable-options\", \"--document-private-items\"]" "--frozen" "--message-format=json", kill_on_drop: false }