Custom types - getting "ERROR: type 'x' already exists" in multiple cases

[nguiard]

Hi,
Thanks for this awesome library.

I'm fooling around with custom types.

• This works:

use pgx::prelude::*;
use serde::{Serialize, Deserialize};

pgx::pg_module_magic!();


#[derive(Debug, Serialize, Deserialize, PostgresType)]
pub struct A;

#[pg_extern]
fn myfunc() -> A {
    A
}

• However, this does not anymore, when you wrap the return in a Result

use pgx::prelude::*;
use pgx::spi;
use serde::{Serialize, Deserialize};

pgx::pg_module_magic!();


#[derive(Debug, Serialize, Deserialize, PostgresType)]
pub struct A;

#[pg_extern]
fn myfunc() -> Result<A, spi::Error> {
    Ok(A)
}

It compiles fine of course, but when you try to create extension, you get ERROR: type "a" already exists. (also, it's not dependent on spi, changing spi::Error to std::error::Error produces the same result).

It seems that this is tied to ordering problems in the generated sql file. Because this also fails with the same error:

use pgx::prelude::*;
use pgx::spi;
use serde::{Serialize, Deserialize};

pgx::pg_module_magic!();


#[derive(Debug, Serialize, Deserialize, PostgresType)]
pub struct B;

#[derive(Debug, Serialize, Deserialize, PostgresType)]
pub struct A;

#[pg_extern]
fn myfunc(_x: B) -> Result<A, spi::Error> {
    Ok(A)
}

But, rename struct A to struct Z, and it now works!

use pgx::prelude::*;
use pgx::spi;
use serde::{Serialize, Deserialize};

pgx::pg_module_magic!();


#[derive(Debug, Serialize, Deserialize, PostgresType)]
pub struct B;

#[derive(Debug, Serialize, Deserialize, PostgresType)]
pub struct Z;

#[pg_extern]
fn myfunc(_x: B) -> Result<Z, spi::Error> {
    Ok(Z)
}

[eeeebbbbrrrr]

Interesting bug. Sounds like our handling of Result<T> isn't adding itself to the dependency graph in the right place.

[marcusllorente-msft]

Hi, I am encountering the same error as well. @nguiard I don't see why renaming the struct from A to Z would work, and I can't seem to make it work on my end when replicating the change from struct A to struct Z. Any insight?

[eeeebbbbrrrr]

@marcusllorente-msft which pgrx version? Have you tried with the v0.10.0 betas?

[marcusllorente-msft]

@eeeebbbbrrrr I'm using crate v0.9.8. I tried following the steps to get the beta, but I am getting this error: pgrx-0.9.8` shouldn't be used with `cargo-pgrx-0.10.0-beta.0`, please use `pgrx = "~0.10.0-beta.0"` in your Cargo.toml`. and my Cargo.toml file includes this line: pgrx = "~0.10.0-beta.0" in the dependencies section. I am new to PGRX so apologies if this is a silly question

[eeeebbbbrrrr]

oh, yeah, you'd need to install the beta version of cargo-pgrx directly too: cargo install cargo-pgrx --version 0.10.0-beta.1 --locked

Note that I typed beta.1 here, so you'd update your Cargo.toml as well.

I don't know for certain if this is fixed in the 0.10.0 betas but there was some work around better understanding Result return types. We haven't had a chance to actually look at this issue specifically.

If beta.1 doesn't help here then I'll commit to look at this directly next week.

[marcusllorente-msft]

@eeeebbbbrrrr Just tried installing both beta.1 and beta.0, both seem to raise errors when I include the correct pgrx version:
0:pgrx-0.9.8shouldn't be used withcargo-pgrx-0.10.0-beta.1, please use pgrx = "~0.10.0-beta.1"in yourCargo.toml., perhaps I am missing something? I did the cargo install and cargo pgrx init commands too.

[eeeebbbbrrrr]

It seems like you've got cargo-pgrx installed correctly and now need to update your extension's Cargo.toml file to use that exact version. That's what the error message is trying to communicate -- maybe we need to work on the wording.

It's required that the installed cargo-pgrx and the pgrx = "x.y.z" dependency version in Cargo.toml match.

[marcusllorente-msft]

@eeeebbbbrrrr I see. I meant to say that I did include the correct dependency version in my .toml file when I tried both beta.1 and beta.0, but each one raised an error saying that pgrx-0.9.8 is the currently used dependency when I already updated that. Do you have a sample Cargo.toml file that works using this beta.1 version that I can use? Perhaps I am missing a tilde or a digit somewhere along the way

[eeeebbbbrrrr]

Maybe you aren't picking up the proper cargo-pgrx. What does cargo pgrx --version report?

Also, all our examples work: https://github.com/pgcentralfoundation/pgrx/tree/master/pgrx-examples

[marcusllorente-msft]

@eeeebbbbrrrr it returns: cargo-pgrx 0.10.0-beta.1. My dependencies look like this:
[dependencies] pgrx = "~0.10.0-beta.1"

[eeeebbbbrrrr]

hmm. Change that ~ to an = and see what happens.

[marcusllorente-msft]

@eeeebbbbrrrr Just tried, getting the same error: 0: pgrx-0.9.8 shouldn't be used with cargo-pgrx-0.10.0-beta.1, please use pgrx = "~0.10.0-beta.1" in your Cargo.toml.