A 1:1 port of the Bash script to Python for use on Windows.
Pulls some parts of #1068 but much more minimal. Avoids an additional
dependency on `requests`. Because we require `zstandard` to unzip the
distributions we unfortunately cannot be dependency free and cannot have
`bootstrap.sh` download the Python version needed to run this script
without it doing a non-trivial amount of work.
Retains the Bash script for now so you can bootstrap without Python
available. I may drop it in the future?
Replaces https://github.com/astral-sh/puffin/pull/1068 and #1070 which
were more complicated than I wanted.
- Introduces a `.python-versions` file which defines the Python versions
needed for development
- Adds a Bash script at `scripts/bootstrap/install` which installs the
required Python versions from `python-build-standalone` to `./bin`
- Checks in a `versions.json` file with metadata about available
versions on each platform and a `fetch-version` Python script derived
from `rye` for updating the versions
- Updates CI to use these Python builds instead of the `setup-python`
action
- Updates to the latest packse scenarios which require Python 3.8+
instead of 3.7+ since we cannot use 3.7 anymore and includes new test
coverage of patch Python version requests
- Adds a `PUFFIN_PYTHON_PATH` variable to prevent lookup of system
Python versions for isolation during development
Tested on Linux (via CI) and macOS (locally) — presumably it will be a
bit more complicated to do proper Windows support.
## Background
In virtual environments, we want to install python programs as console
commands, e.g. `black .` over `python -m black .`. They may be called
[entrypoints](https://packaging.python.org/en/latest/specifications/entry-points/)
or scripts. For entrypoints, we're given a module name and function to
call in that module.
On Unix, we generate a minimal python script launcher. Text files are
runnable on unix by adding a shebang at their top, e.g.
```python
#!/usr/bin/env python
```
will make the operating system run the file with the current python
interpreter. A venv launcher for black in `/home/ferris/colorize/.venv`
(module name: `black`, function to call: `patched_main`) would look like
this:
```python
#!/home/ferris/colorize/.venv/bin/python
# -*- coding: utf-8 -*-
import re
import sys
from black import patched_main
if __name__ == "__main__":
sys.argv[0] = re.sub(r"(-script\.pyw|\.exe)?$", "", sys.argv[0])
sys.exit(patched_main())
```
On windows, this doesn't work, we can only rely on launching `.exe`
files.
## Summary
We use posy's rust implementation of a trampoline, which is based on
distlib's c++ implementation. We pre-build a minimal exe and append the
launcher script as stored zip archive behind it. The exe will look for
the venv python interpreter next to it and use it to execute the
appended script.
The changes in this PR make the `black` entrypoint work:
```powershell
cargo run -- venv .venv
cargo run -q -- pip install black
.\.venv\Scripts\black --version
```
Integration with our existing tests will be done in follow-up PRs.
## Implementation and Details
I've vendored the posy trampoline crate. It is a formatted, renamed and
slightly changed for embedding version of
https://github.com/njsmith/posy/pull/28.
The posy launchers are smaller than the distlib launchers, 16K vs 106K
for black. Currently only `x86_64-pc-windows-msvc` is supported. The
crate requires a nightly compiler for its no-std binary size tricks.
On windows, an application can be launched with a console or without (to
create windows instead), which needs two different launchers. The gui
launcher will subsequently use `pythonw.exe` while the console launcher
uses `python.exe`.
## Summary
This PR adds a release workflow powered by `cargo-dist`. It's similar to
the version that's PR'd in Ruff
(https://github.com/astral-sh/ruff/pull/9559), with the exception that
it doesn't include the Docker build or the "update dependents" step for
pre-commit.
Zanie Blue