`proc-macro2@1.0.56` breaks `quote!` line formatting

[obrok]

It seems that upgrading to proc-macro2 >=1.0.56 breaks how newlines are handled in the generated code.

Steps to reproduce:

1. cargo update -p proc-macro2 --precise 1.0.56
2. cargo test

Note that it seems to work correctly for 1.0.55.

[udoprog]

Thanks for the report!

This is due to dtolnay/proc-macro2#383 which is in preparation of a maybe breaking nightly upcoming change.

Seems like things are gonna be broken for a while. Welcome to nightly :)

[obrok]

I locked to an older proc-macro2 for now in my package... Do you think maybe you should specify proc-macro2 <=1.0.55 in your deps until this is fixed over there?

[udoprog]

Hm... maybe. It's going to instantly break if / once that nightly change lands, so I'm not sure there's a ton of benefit to be had by making a release right now. I'll have to do one anyway once the new API is available. I'll think about it.

[udoprog]

We might also soon see stable support for line/column information, meaning the years long wait would be over 🎉

rust-lang/rust#54725 (comment)

[obrok]

Well, difficult for me to weigh in, because I don't have a good grasp on the timescales involved. Thanks for the explanation though.

[udoprog]

I'll bake a new release if rust-lang/rust#111571 is not out on nightly within the week. Sorry for the inconvenience. Keeping this open to track the issue.

[obrok]

Not a problem and thanks for the quick responses!

[kklas]

Also affected by this. Can't pin proc-macro2 to 1.0.55 because other dependencies I'm using require a higher version.

[udoprog]

All right. Time to start building a workaround, we'll have to bypass proc-macro2 for now - because the API there has been stripped before the new nightly API is available. I'll see what I can do.

[udoprog]

Also affected by this. Can't pin proc-macro2 to 1.0.55 because other dependencies I'm using require a higher version.

@kklas I'm curious; Which other dependency?

[kklas]

I'm building a code generator tool against https://github.com/MystenLabs/sui. It's a huge repo pulling in a lot of transitive dependencies. This is what I get trying to pin proc-macro2 to 1.0.55:

$ cargo update -p proc-macro2@1.0.59 --precise 1.0.55
    Updating crates.io index
error: failed to select a version for the requirement `proc-macro2 = "^1.0.59"`
candidate versions found which didn't match: 1.0.55
location searched: crates.io index
required by package `syn v2.0.18`
    ... which satisfies dependency `syn = "^2.0.9"` (locked to 2.0.18) of package `async-trait v0.1.68`
    ... which satisfies dependency `async-trait = "^0.1.57"` (locked to 0.1.68) of package `anemo v0.0.0 (https://github.com/mystenlabs/anemo.git?rev=baa7cfc3ae841f88c2ff773396c5a803c377d054#baa7cfc3)`
    ... which satisfies git dependency `anemo` (locked to 0.0.0) of package `anemo-cli v0.0.0 (https://github.com/mystenlabs/anemo.git?rev=baa7cfc3ae841f88c2ff773396c5a803c377d054#baa7cfc3)`
    ... which satisfies git dependency `anemo-cli` (locked to 0.0.0) of package `workspace-hack v0.1.0 (https://github.com/MystenLabs/sui?branch=releases/sui-v1.2.0-release#5938864a)`
    ... which satisfies git dependency `workspace-hack` (locked to 0.1.0) of package `mysten-metrics v0.7.0 (https://github.com/MystenLabs/sui?branch=releases/sui-v1.2.0-release#5938864a)`
    ... which satisfies git dependency `mysten-metrics` (locked to 0.7.0) of package `sui-adapter-latest v0.1.0 (https://github.com/MystenLabs/sui?branch=releases/sui-v1.2.0-release#5938864a)`
    ... which satisfies git dependency `sui-adapter` (locked to 0.1.0) of package `sui-move-build v0.0.0 (https://github.com/MystenLabs/sui?branch=releases/sui-v1.2.0-release#5938864a)`
    ... which satisfies git dependency `sui-move-build` (locked to 0.0.0) of package `generator v0.1.0 (/home/user/work/sui-client-gen/generator)`
perhaps a crate was updated and forgotten to be re-vendored?

Even if I could fix this (which I can't) there would probably be others.