No function or associated item named insert_types, create_type, get_full_path for VecDeque and usize on Anchor 0.30

[megatunger]

I could not build the program since upgrade to Anchor 0.30. It happened if I try to add a field with usize or VecDeq type in struct. Here is a simple replication of this issue

#[account]
pub struct Pool {
    pub id: u64,
    pub size: usize,
    pub workers: VecDeque<Pubkey>,
}

Old: Anchor 0.29.0, Solana 1.18.14 -> working

New: Anchor 0.30.0, Solana 1.18.14 -> not working

List of errors:

error[E0599]: no function or associated item named insert_types found for struct VecDeque in the current scope
error[E0599]: no function or associated item named insert_types found for type usize in the current scope
error[E0599]: no function or associated item named create_type found for struct VecDeque in the current scope
error[E0599]: no function or associated item named get_full_path found for struct usize in the current scope
error[E0599]: no function or associated item named get_full_path found for struct VecDeque in the current scope

[acheroncrypto]

usize and VecDeque types are not supported in the IDL spec. The reason it used to work before 0.30.0 is because IDL generation would just make everything unknown as a defined type, which resulted in build succeeding but also with an unusable IDL. You can verify this by building your program with 0.29.0 and try to use that IDL client side.

You can, however, include any type in the IDL if you implement IdlBuild trait for that type. See "Customization" section of #2824 and this example.

[megatunger]

Thanks for you explaination!