Compilation in setuptools_rust fails with `1.70.0-nightly` toolchain

[yasuo-ozu]

Assumptions

• problematic toolchain
  -- rustc 1.70.0-nightly (db0cbc48d 2023-03-26)
  -- rustc 1.70.0-nightly (478cbb42b 2023-03-28)
• toolchain not affected
  -- rustc 1.68.0-stable

Description

wheel package generation fails with latest toolchain, when crate-type = ["cdylib"] is not contained in Cargo.toml.

Cause

The following command in build process will not work:

cargo rustc --lib --message-format=json-render-diagnostics --manifest-path Cargo.toml --release -v --features 'python pyo3/extension-module' --no-default-features -- --crate-type cdylib

Instead, following works:

cargo rustc --lib --message-format=json-render-diagnostics --manifest-path Cargo.toml --release -v --features 'python pyo3/extension-module' --no-default-features --crate-type cdylib

Workaround

any of the following avoids the bug:

• Write crate-type = ["cdylib"] in Cargo.toml
• Write args=["--crate-type", "cdylib"] in initializer of RustExtension

Sample:

                RustExtension(
                    'namespace.package', 'Cargo.toml',
                    binding = Binding.PyO3,
                    args = ["--crate-type", "cdylib"],
                )

I will create PRs later.

[messense]

The following command in build process will not work:

cargo rustc --lib --message-format=json-render-diagnostics --manifest-path Cargo.toml --release -v --features 'python pyo3/extension-module' --no-default-features -- --crate-type cdylib

What's the error message?

[yasuo-ozu]

With following commands:

$ cd examples/html-py-ever
$ rustup default nightly
$ rustc --version
rustc 1.70.0-nightly (478cbb42b 2023-03-28)
$ vi Cargo.toml
# Here, remove line 'crate-type = ["dyllib"]'
$ cargo rustc --lib --message-format=json-render-diagnostics --manifest-path Cargo.toml --release -v --features pyo3/extension-module -- --crate-type cdylib

I get

   Compiling html-py-ever v0.1.0 (/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever)
     Running `rustc --crate-name html_py_ever --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=159 --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no --crate-type cdylib -C metadata=46a88f8ad81bd4e9 -C extra-filename=-46a88f8ad81bd4e9 --out-dir /home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps -L dependency=/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps --extern kuchiki=/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps/libkuchiki-17d7bf24f9e68077.rmeta --extern pyo3=/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps/libpyo3-d3ecaf764808e42c.rmeta --extern tendril=/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps/libtendril-e113a85045e3a1e9.rmeta`
error: crate `pyo3` required to be available in rlib format, but was not found in this form

error: crate `tendril` required to be available in rlib format, but was not found in this form

error: crate `kuchiki` required to be available in rlib format, but was not found in this form

error: could not compile `html-py-ever` (lib) due to 3 previous errors

Caused by:
  process didn't exit successfully: `rustc --crate-name html_py_ever --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=159 --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no --crate-type cdylib -C metadata=46a88f8ad81bd4e9 -C extra-filename=-46a88f8ad81bd4e9 --out-dir /home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps -L dependency=/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps --extern kuchiki=/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps/libkuchiki-17d7bf24f9e68077.rmeta --extern pyo3=/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps/libpyo3-d3ecaf764808e42c.rmeta --extern tendril=/home/yasuo/ghq/github.com/PyO3/setuptools-rust/examples/html-py-ever/target/release/deps/libtendril-e113a85045e3a1e9.rmeta` (exit status: 1)

[yasuo-ozu]

Actually I cannot figure out which change on rustc break the compatibility.
(it occurs between ff4b772 ... 8a73f50)

Recently --crate-type option is implemented in cargo, so I think it is safer to use --crate-type option on cargo.