proc macro are not rebuilt on IDL changes

[Arrowana]

This can help fix it by tracking the json file, unfortunately nightly and doesn't look like it is ready to be stabilized
rust-lang/rust#99515

Scenario:

Dependency program has a new endpoint, update IDL, still no cpi method for it...

The solution right now is cargo clean then cargo build

[0xfourzerofour]

You could also do this by using a build.rs file and check changes there