## Summary
This PR enables the proof-of-concept resolver to backtrack by way of
using the `pubgrub-rs` crate.
Rather than using PubGrub as a _framework_ (implementing the
`DependencyProvider` trait, letting PubGrub call us), I've instead
copied over PubGrub's primary solver hook (which is only ~100 lines or
so) and modified it for our purposes (e.g., made it async).
There's a lot to improve here, but it's a start that will let us
understand PubGrub's appropriateness for this problem space. A few
observations:
- In simple cases, the resolver is slower than our current (naive)
resolver. I think it's just that the pipelining isn't as efficient as in
the naive case, where we can just stream package and version fetches
concurrently without any bottlenecks.
- A lot of the code here relates to bridging PubGrub with our own
abstractions -- so we need a `PubGrubPackage`, a `PubGrubVersion`, etc.
We can always restore these from history, but right now, it feels a lot
more productive to just hit PyPI directly for our integration tests,
since we don't have to spend time figuring out mocks.
Mocks out the PyPI client using some checked-in fixtures. The test is
very basic, and I'm not very happy with all the ceremony around the
mocks and such, but it's an interesting experiment at least.
When we go to install a locked `requirements.txt`, if a wheel is already
available in the local cache, and matches the version specifiers, we can
just use it directly without fetching the package metadata. This speeds
up the no-op case by about 33%.
Closes https://github.com/astral-sh/puffin/issues/48.
The setup is now as follows:
- All user-facing logging goes through `tracing` at an `info` leve.
(This excludes messages that go to `stdout`, like the compiled
`requirements.txt` file.)
- We have `--quiet` and `--verbose` command-line flags to set the
tracing filter and format defaults. So if you use `--verbose`, we
include timestamps and targets, and filter at `puffin=debug` level.
- However, we always respect `RUST_LOG`. So you can override the
_filter_ via `RUST_LOG`.
For example: the standard setup filters to `puffin=info`, and doesn't
show timestamps or targets:
<img width="1235" alt="Screen Shot 2023-10-08 at 3 41 22 PM"
src="54ca4db6-c66a-439e-bfa3-b86dee136e45">
If you run with `--verbose`, you get debug logging, but confined to our
crates:
<img width="1235" alt="Screen Shot 2023-10-08 at 3 41 57 PM"
src="c5c1af11-7f7a-4038-a173-d9eca4c3630b">
If you want verbose logging with _all_ crates, you can add
`RUST_LOG=debug`:
<img width="1235" alt="Screen Shot 2023-10-08 at 3 42 39 PM"
src="0b5191f4-4db0-4db9-86ba-6f9fa521bcb6">
I think this is a reasonable setup, though we can see how it feels and
refine over time.
Closes https://github.com/astral-sh/puffin/issues/57.
This PR modifies the `install-wheel-rs` (and a few other crates) to get
everything playing nicely. Specifically, CI should pass, and all these
crates now use workspace dependencies between one another.
As part of this change, I split out the wheel name parsing into its own
`wheel-filename` crate, and the compatibility tag parsing into its own
`platform-tags` crate.
This PR modifies the PEP 440 and PEP 508 crates to pass CI, primarily by
fixing all lint violations.
We're also now using these crates in the workspace via `path`.
(Previously, we were still fetching them from Cargo.)
