Inside a given `site-packages` directory, *.pyc files live in
`__pycache__` directories. These are created by the Python interpreter
when a module is imported in order to speed up future access to the
imported module.
These can be left behind when formulae are uninstalled, which results in
erroneous success in importing the modules they were originally compiled
for.
Let's fix that by cleaning these up. In the top-level `__pycache__`
directory, we use the `Pathname#prune?` extension in order to determine
whether a `*.pyc` file is old enough to clean up. In other directories,
we clean them up when they are all that remains in a given module's
tree.
Removing these `*.pyc` files will make `python3` regenerate them when
required, so deleting them is relatively safe. The worst consequence is
slightly slower module import times.
Closes#13701.
Occasionally, a new version of Rust will cause failures in dependents.
See, for example, Homebrew/homebrew-core#107818.
This change will allow us to get a fuller backtrace in CI, which will
also make it easier to submit bug reports upstream.
Without this change, recovering a full backtrace requires installing the
new version of Rust and rebuilding the failing formula from source. Both
these steps can be skipped if we set `RUST_BACKTRACE` when retrying a
failing test.
Some formulae declare multiple Python dependencies, and they can appear
in any order in the `deps` array. Let's make sure to prefer the newest
one when adding their `libexec/"bin"` directory to `PATH`.
Some formulae are flexible about the version of Python3 that they use.
However, when we use `#detected_python_shebang` on these formulae, they
become coupled to the specific version of Python3 declared in the
formula.
This is harmful because
1. it prevents us from using `uses_from_macos "python"` even in formulae
where we should be able to
2. it forces us to rebuild the formula whenever we make changes to the
Python dependency when nothing but the shebang would have changed as
a consequence of the rebuild
For an example of this, see Homebrew/homebrew-core#107905.
I'd also like to do this to get rid of some really terrible hacks we
have in `glib-utils` as a means of decoupling `glib` from the specific
versioned Python dependency it used to have.
See Homebrew/homebrew-core#103916, or Homebrew/homebrew-core#106045 for
a proposal to give the same treatment to `gobject-introspection`.
Due to limitations of the test framework, this only tests
that the command with the --debug-symbols
flag succeeds and that on MacOS the `dsymutil` is run.
