How do I specify an interpreter during build?

[pmeier]

Either I'm to dense to find it, but so far I have no idea what I need to pass to maturin build --interpreter=???. Help message is not really helpful:

$ maturin build --help | grep -A1 -e --interpreter
    -i, --interpreter <INTERPRETER>...
            The python versions to build wheels for, given as the names of the interpreters

I tried the "raw" specifiers such as "3.8", but for that I'm getting

🔗 Found pyo3 bindings with abi3 support for Python ≥ 3.7
🐍 Not using a specific python interpreter
[...]
📦 Built wheel for abi3 Python ≥ 3.7 [...]

Using the tags from PEP 427, i.e. "py38", "cp38" fails:

🔗 Found pyo3 bindings with abi3 support for Python ≥ 3.7
💥 maturin failed
  Caused by: The given list of python interpreters is invalid
  Caused by: Python interpreter `py38` doesn't exist

From the failure message it seems I should also be able to build multiple wheels at the same time by passing a list of interpreters. Since the "raw" specifier was the only one that didn't fail, I tried a comma-separated list:

$ maturin build --interpreter=3.8,3.9
[...]
🔗 Found pyo3 bindings with abi3 support for Python ≥ 3.7
💥 maturin failed
  Caused by: The given list of python interpreters is invalid
  Caused by: Python interpreter `3.8,3.9` doesn't exist

What am I missing here? Happy to contribute to improve the help message or documentation.

[konstin]

I didn't realize we wrote it that ambiguously, it's not actually the name of the interpreter, but the executable like you would in the shell, such as python3.7 or /usr/bin/python3.8

[konstin]

Oh sorry, it seems you're the abi3 feature of pyo3. In that case no need for using any specific python interpreter, the wheel compatibility is determined by pyo3 features; neither pyo3 nor maturin do even need to query or link python in that case.

[pmeier]

Oh sorry, it seems you're the abi3 feature of pyo3.

Yes, i have

[dependencies.pyo3]
version = "0.17"
features = ["extension-module", "abi3-py37"]

in my Cargo.toml.

In that case no need for using any specific python interpreter, the wheel compatibility is determined by pyo3 features; neither pyo3 nor maturin do even need to query or link python in that case.

Ok, how can I get the "proper" wheel tags in that case? Right now every wheel will be XXX-cp37-abi3-YYY. AFAIK, pip will reject that for every other Python version. Do I copy the wheel and just sed the Python version? Do I sed the "abi-py37" in Cargo.toml?

[konstin]

nope, those wheels can be installed on any later python 3 version! abi3 is really cool because it allows you to build only one wheel for all python versions you want to support

[messense]

FYI, here is the abi3 docs in pyo3 user guide: https://pyo3.rs/v0.17.3/building_and_distribution.html#py_limited_apiabi3

[pmeier]

Oh nice, I didn't know about that. Thanks!