Anchor build errors due to 'getrandom' and 'let...else'

Question

Anchor Version - 0.27.0 Solana Version - 1.14.19 Rust/Cargo Version 1.70

returned to my solana dev server for first time in a while. Start a project with anchor init, and attempt to build the hello world just to check everything is OK.

First I get an error I haven't seen before:

error: target is not supported, for more information see: https://docs.rs/getrandom/#unsupported-targets --> src/lib.rs:286:9

I can resolve that by adding getrandom = { version = "0.2.2", features = ["custom"] } to the cargo.toml file, but that seems like a hack. I've never had to use that before.

After that I get another error:

error[E0658]: 'let...else' statements are unstable

in relation to solana-frozen-abi-macro-1.16.0/src/lib.rs

I'm unable to fix that issue.

So build fails with: could not compile 'solana-frozen-abi-macro' due to 2 previous errors

Is this due to the rust update to 1.70? It's the only thing I can think I've changed.

Answer 1

Try using the following dependencies.

[dependencies]
anchor-lang = "0.27.0"
anchor-spl = "0.27.0"
getrandom = { version = "0.2.9", features = ["custom"] }
solana-program = "=1.14.17"
winnow="=0.4.1"
toml_datetime="=0.6.1"

From the Anchor discord it seems there's some compatibility issues with the 1.16 release.

seems like new projects will not work unless they fixate the solana-program version to 1.14.x you can keep using that version and add solana-program = "=1.14.17" in your Cargo.toml

Related to this: https://github.com/solana-labs/solana/issues/31428