undefined reference with pyo3 feature extension-module and multiple-pymethods on linux

[sun-rs]

I have a rust package which use pyo3, it create a python extension on windows.

[lib]
name = "test"
crate-type = ["cdylib","lib"]

[dependencies]
pyo3 = { version = "0.16.2", features = ["hashbrown", "extension-module", "multiple-pymethods"] }

[features]
extension-module = ["pyo3/extension-module"]
default = ["extension-module"]

It works well on windows 10/11, but recently I removed these code to linux(using wsl2 ubuntu). When I execute cargo test or cargo run(I have a main.rs) on linux, it raises error: linking with cc failed: exit status: 1 and a lot of undefined reference to some pyo3 functions. Also cargo run --no-default-features has the same error.

If I remove the feature extension-module, cargo test or cargo run could work through.

What's the reason about these linking error? Should I pass some cargo flags into build.rs or remove multiple-pymethods?

[messense]

See https://pyo3.rs/v0.17.3/faq#i-cant-run-cargo-test-or-i-cant-build-in-a-cargo-workspace-im-having-linker-issues-like-symbol-not-found-or-undefined-reference-to-_pyexc_systemerror

[dependencies]
pyo3 = { version = "0.16.2", features = ["hashbrown", "extension-module", "multiple-pymethods"] }

[features]
extension-module = ["pyo3/extension-module"]
default = ["extension-module"]

You should remove extension-module from pyo3 = { version = "0.16.2", features = ["hashbrown", "extension-module", "multiple-pymethods"] }, otherwise it's always enabled.

[sun-rs]

I can't remove extension-module because the package is for python extension. I tried to remove multiple-pymethods and cargo run works fine. I think this is what https://github.com/PyO3/pyo3/issues/341#issuecomment-888543380 talked about.

[messense]

I tried to remove multiple-pymethods and cargo run works fine.

Then you can just remove multiple-pymethods if you don't rely on multiple #[pymethods]s.

I can't remove extension-module because the package is for python extension.

You have already enabled it via custom feature flags, that is

[features]
extension-module = ["pyo3/extension-module"]
default = ["extension-module"]

namely the default extension-module enables it conditionally to allow cargo test --no-default-features to disable extension-module. But pyo3 = { version = "0.16.2", features = ["hashbrown", "extension-module", "multiple-pymethods"] } always enables extension-module which defeats the purpose of your custom feature flags.

To learn more about cargo features, see https://doc.rust-lang.org/cargo/reference/features.html