PyO3 can't find Rust compiler on M1, despite cargo / rustc / rustup installed and on path

Question

I'm trying to get PyO3 working on my Mac M1 mini. If I follow the steps to get started with PyO3:

$ mkdir string_sum
$ cd string_sum
$ python -m venv .env
$ source .env/bin/activate
$ pip install maturin

I get "rustc...is not installed or not in PATH":

> maturin init
✔  What kind of bindings to use? · pyo3
  ✨ Done! Initialized project /Users/tweedle/projects/string_sum
> maturin develop
 maturin failed
  Caused by: rustc, the rust compiler, is not installed or not in PATH. This package requires Rust and Cargo to compile extensions. Install it through the system's package manager or via https://rustup.rs/.

I see this error come up a lot in the PyO3 issues, but it's generally solved by installing rustup. But I have rustup installed and on path:

❯ rustc --version
rustc 1.58.1 (db9d1b20b 2022-01-20)
> rustup which rustc
/Users/tweedle/.rustup/toolchains/stable-aarch64-apple-darwin/bin/rustc
> export PATH="$PATH:~/.rustup/toolchains/stable-aarch64-apple-darwin/bin:~/.cargo/bin"
> maturin develop
 maturin failed
  Caused by: rustc, the rust compiler, is not installed or not in PATH. This package requires Rust and Cargo to compile extensions. Install it through the system's package manager or via https://rustup.rs/.

(Added to PATH again just to make sure.) I've also tried the x86 toolchain, same results. Cargo build also runs fine on the maturin-generated string_sum rust code:

> cargo build
    Updating crates.io index
   Compiling proc-macro2 v1.0.36
   Compiling unicode-xid v0.2.2
   Compiling pyo3-build-config v0.15.1
   Compiling syn v1.0.86
   Compiling proc-macro-hack v0.5.19
   Compiling once_cell v1.9.0
   Compiling libc v0.2.116
   Compiling cfg-if v1.0.0
   Compiling parking_lot_core v0.8.5
   Compiling scopeguard v1.1.0
   Compiling smallvec v1.8.0
   Compiling unindent v0.1.7
   Compiling instant v0.1.12
   Compiling lock_api v0.4.6
   Compiling quote v1.0.15
   Compiling parking_lot v0.11.2
   Compiling pyo3 v0.15.1
   Compiling paste-impl v0.1.18
   Compiling paste v0.1.18
   Compiling pyo3-macros-backend v0.15.1
   Compiling indoc-impl v0.3.6
   Compiling indoc v0.3.6
   Compiling pyo3-macros v0.15.1
   Compiling string_sum v0.1.0 (/Users/tweedle/projects/string_sum)
    Finished dev [unoptimized + debuginfo] target(s) in 9.73s

Is it something weird with my M1 setup, my homebrew setup, my rust setup, my python setup, or something else I missed?

More info:

> neofetch
                    'c.          tweedle@mini.local
                 ,xNMM.          ------------------
               .OMMMMo           OS: macOS 12.2 21D49 arm64
               OMMM0,            Host: Macmini9,1
     .;loddo:' loolloddol;.      Kernel: 21.3.0
   cKMMMMMMMMMMNWMMMMMMMMMM0:    Uptime: 1 day, 2 hours, 12 mins
 .KMMMMMMMMMMMMMMMMMMMMMMMWd.    Packages: 116 (brew)
 XMMMMMMMMMMMMMMMMMMMMMMMX.      Shell: bash 5.1.16
;MMMMMMMMMMMMMMMMMMMMMMMM:       Resolution: 1920x1080
:MMMMMMMMMMMMMMMMMMMMMMMM:       DE: Aqua
.MMMMMMMMMMMMMMMMMMMMMMMMX.      WM: Rectangle
 kMMMMMMMMMMMMMMMMMMMMMMMMWd.    Terminal: kitty
 .XMMMMMMMMMMMMMMMMMMMMMMMMMMk   CPU: Apple M1
  .XMMMMMMMMMMMMMMMMMMMMMMMMK.   GPU: Apple M1
    kMMMMMMMMMMMMMMMMMMMMMMd     Memory: 1975MiB / 16384MiB
     ;KMMMMMMMWXXWMMMMMMMk.
       .cooc,.    .,coo:.

> rustup --version
rustup 1.24.3 (ce5817a94 2021-05-31)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.58.1 (db9d1b20b 2022-01-20)`
> rustc --version
rustc 1.58.1 (db9d1b20b 2022-01-20)
> python --version
Python 3.9.10
> maturin --version
maturin 0.12.6

I've also tried using setuptools-rust to similar effect, both calling setup.py directly and also using pip install ..

PyO3 can't find Rust compiler on M1, despite cargo / rustc / rustup installed and on path

0 Answers0