build version issue

[z-hanwen]

here is my anchor build error.
error: rustc 1.79.0-dev is not supported by the following package: Note that this is the rustc version that ships with Solana tools and not your system's rustc version. Use solana-install updateor head over to https://docs.solanalabs.com/cli/install to install a newer version. bytemuck_derive@1.9.2 requires rustc 1.84 Either upgrade rustc or select compatible dependency versions withcargo update @ --precise where is the latest version supporting rustc 1.79.0-dev

here is my all versions;
solana --version solana-cli 2.1.16 (src:a5744e79; feat:3271415109, client:Agave)

rustc --version rustc 1.85.1 (4eb161250 2025-03-15)

anchor --version anchor-cli 0.31.0

Should I lower the version of rust?？

[hanool]

Same issue here. I also tried to add rust-toolchain.toml to override the rust toolchain version of 1.79.0 but nothing changed

[toolchain]
channel = "1.79.0"

[z-hanwen]

Same issue here. I also tried to add rust-toolchain.toml to override the rust toolchain version of 1.79.0 but nothing changed

[toolchain]
channel = "1.79.0"

I found a way to solve this problem. you could wirte this in anchor.toml [toolchain] channel = "1.79.0" and write this in cargo.toml [dependencies] anchor-lang = "0.30.1" anchor-spl = "0.30.1" bytemuck_derive = "=1.7.0"
be careful , it is the cargo.toml in the programs folder, not package.json above that。
And, if you use this solution you will only be able to use the 0.30.1 version of anchor

[jacobcreech]

We're planning a patch release to make things work out-of-the-box, but in the meantime, you can just add:

bytemuck_derive = "=1.8.1"

Fix found in #3610

[z-hanwen]

We're planning a patch release to make things work out-of-the-box, but in the meantime, you can just add:

bytemuck_derive = "=1.8.1"

Fix found in #3610

thanks ,that's really work

[hanool]

Thank you for letting me know the workaround. For anyone who might face the same issue, you can add bytemuck_derive = "=1.8.1" to Cargo.toml to use the anchor version 0.31.0 as is.

[hanool]

So based on the issue #3610 , I can't use zero copy because this workaround only work when the bytemuck derive is not used?

[acheroncrypto]

See #3606 (comment)