Previously, we were assuming that `which <python>` return the path to
the python executable. This is not true when using pyenv shims, which
are bash scripts. Instead, we have to use `sys.executable`. Luckily,
we're already querying the python interpreter and can do it in that
pass.
We are also not allowed to cache the execution of the python interpreter
through the shim because pyenv might change the target. As a heuristic,
we check whether `sys.executable`, the real binary, is the same our
canonicalized `which` result.
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Co-authored-by: Zanie Blue <contact@zanie.dev>
Previously, we had two python interpreter metadata structs, one in
gourgeist and one in puffin. Both would spawn a subprocess to query
overlapping metadata and both would appear in the cli crate, if you
weren't careful you could even have to different base interpreters at
once. This change unifies this to one set of metadata, queried and
cached once.
Another effect of this crate is proper separation of python interpreter
and venv. A base interpreter (such as `/usr/bin/python/`, but also pyenv
and conda installed python) has a set of metadata. A venv has a root and
inherits the base python metadata except for `sys.prefix`, which unlike
`sys.base_prefix`, gets set to the venv root. From the root and the
interpreter info we can compute the paths inside the venv. We can reuse
the interpreter info of the base interpreter when creating a venv
without having to query the newly created `python`.
konsti