unknown feature proc_macro_span_shrink

[rlovell3]

I'm at a bit of a loss on this one. I'm using rustc 1.73.0-nightly with cargo-leptos to build a simple web stack, and I keep getting a compile error that is focusing on proc-macro2-1.0.59. This is so deep into the bowels of the compiler that I'm not even sure of which direction I should be looking. If I remove the crate from inside my .cargo/registry/src/index.crates.io... it reappears as soon as I try to build (which makes sense, but I can't trace what is calling for it to be installed), and if I try the "RUSTFLAGS='--cfg procmacro2_semver_exempt' cargo build" command, I get an absolute ton of compile errors. Anybody got an idea on how to proceed?

[gftea]

I have same issue in my project's CI run below, https://github.com/gftea/amqprs/actions/runs/5690927521/job/15426552955?pr=104

Run RUST_LOG=trace cargo llvm-cov --all-features --lcov --output-path ./lcov.info
warning: some crates are on edition 2021 which defaults to `resolver = "2"`, but virtual workspaces default to `resolver = "1"`
note: to keep the current resolver, specify `workspace.resolver = "1"` in the workspace root's manifest
note: to use the edition 2021 resolver, specify `workspace.resolver = "2"` in the workspace root's manifest
 Downloading crates ...
  Downloaded uriparse v0.[6](https://github.com/gftea/amqprs/actions/runs/5690927521/job/15426552955?pr=104#step:6:7).4
  Downloaded fnv v1.0.7
  Downloaded tokio-rustls v0.23.4
  Downloaded webpki-roots v0.22.6
   Compiling libc v0.2.137
   Compiling proc-macro2 v1.0.47
   Compiling unicode-ident v1.0.5
   Compiling quote v1.0.21
error[E0635]: unknown feature `proc_macro_span_shrink`
  --> /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/proc-macro2-1.0.47/src/lib.rs:92:30
   |
92 |     feature(proc_macro_span, proc_macro_span_shrink)
   |                              ^^^^^^^^^^^^^^^^^^^^^^

For more information about this error, try `rustc --explain E0635`.
error: could not compile `proc-macro2` (lib) due to previous error
warning: build failed, waiting for other jobs to finish...
error: process didn't exit successfully: `/home/runner/.rustup/toolchains/nightly-x[8](https://github.com/gftea/amqprs/actions/runs/5690927521/job/15426552955?pr=104#step:6:9)6_64-unknown-linux-gnu/bin/cargo test --tests --manifest-path /home/runner/work/amqprs/amqprs/Cargo.toml --target-dir /home/runner/work/amqprs/amqprs/target/llvm-cov-target --all-features` (exit status: [10](https://github.com/gftea/amqprs/actions/runs/5690927521/job/15426552955?pr=104#step:6:11)1)

[smoelius]

This looks like a duplicate of #398.

  --> /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/proc-macro2-1.0.47/src/lib.rs:92:30
                                                                                    ^^^^^^

I think cargo update -p proc-macro2 may solve your problem.