anchor build fails to generate IDL with inconsistent errors

[winary]

On a macOS system with Apple M3, the build environment includes:

• solana-cargo-build-sbf version 2.0.20
• platform-tools version 1.42
• Rustc version 1.75.0
• anchor-cli version 0.30.1

When running anchor build, the .so file is successfully generated, but the IDL file is not created. Over multiple builds, the following errors appear inconsistently:

1. Error: invalid number at line 1 column 2
2. Error: invalid type: map, expected a sequence at line 1 column 0
3. Error: IDL doesn't exist
4. Error: invalid type: string "\"CcZxqWCzQtNeCNbffRTnJtSXahNkoccn3K3N6mzwfXsE\"", expected struct IdlConst at line 1 column 50

It seems the build process is unstable and fails to generate a valid IDL file.

[acheroncrypto]

Do you have a reproducable example? I've never seen this error reported before.

It also seems unlikely to me that this would be related to Apple M3, since we just run cargo test with specific flags and capture the output of that command to generate the IDL.

[winary]

demo1: avm use 0.29.0 && anchor init demo1 && cd demo1 && anchor build
demo2: avm use 0.30.1 && anchor init demo2 && cd demo2 && anchor build

it works well at demo1, build successfuly and generate idl file

and demo2 also build successfuly but fail to generate idl file, will get error Error: IDL doesn't exist, after I try several times, it shows different errors like above

solana-cargo-build-sbf 1.18.26
platform-tools v1.41
rustc 1.75.0

anchor-cli 0.30.1

solana-cli 1.18.26 (src:d9f20e95; feat:3241752014, client:SolanaLabs)

@acheroncrypto