## Summary
This is a more robust fix for
https://github.com/astral-sh/uv/issues/2300.
The basic issue is:
- When we resolve, we attempt to pre-fetch the distribution metadata for
candidate packages.
- It's possible that the resolution completes _without_ those pre-fetch
responses. (In the linked issue, this was mainly because we were running
with `--no-deps`, but the pre-fetch was causing us to attempt to build a
package to get its dependencies. The resolution would then finish before
the build completed.)
- In that case, the `Index` will be marked as "waiting" for that
response -- but it'll never come through.
- If there's a subsequent call to the `Index`, to see if we should fetch
or are waiting for that response, we'll end up waiting for it forever,
since it _looks_ like it's in-flight (but isn't). (In the linked issue,
we had to build the source distribution for the install phase of `pip
install`, but `setuptools` was in this bad state from the _resolve_
phase.)
This PR modifies the resolver to ensure that we flush the stream of
requests before returning. Specifically, we now `join` rather than
`select` between the resolution and request-handling futures.
This _could_ be wasteful, since we don't _need_ those requests, but it
at least ensures that every `.wait` is followed by ` .done`. In
practice, I expect this not to have any significant effect on
performance, since we end up using the pre-fetched distributions almost
every time.
## Test Plan
I ran through the test plan from
https://github.com/astral-sh/uv/pull/2373, but ran the build 10 times
and ensured it never crashed. (I reverted
https://github.com/astral-sh/uv/pull/2373, since that _also_ fixes the
issue in the proximate case, by never fetching `setuptools` during the
resolve phase.)
I also added logging to verify that requests are being handled _after_
the resolution completes, as expected.
I also introduced an arbitrary error in `fetch` to ensure that the error
was immediately propagated.
Address a few pedantic lints
lints are separated into separate commits so they can be reviewed
individually.
I've not added enforcement for any of these lints, but that could be
added if desirable.
## Summary
This revives a PR from long ago
(https://github.com/astral-sh/uv/pull/383 and
https://github.com/zanieb/pubgrub/pull/24) that modifies how we deal
with dependencies that are declared multiple times within a single
package.
To quote from the originating PR:
> Uses an experimental pubgrub branch (#370) that allows us to handle
multiple version ranges for a single dependency to the solver which
results in better error messages because the derivation tree contains
all of the relevant versions. Previously, the version ranges were merged
(by us) in the resolver before handing them to pubgrub since only one
range could be provided per package. Since we don't merge the versions
anymore, we no longer give the solver an empty range for conflicting
requirements; instead the solver comes to that conclusion from the
provided versions. You can see the improved error message for direct
dependencies in [this
snapshot](https://github.com/astral-sh/puffin/pull/383/files#diff-a0437f2c20cde5e2f15199a3bf81a102b92580063268417847ec9c793a115bd0).
The main issue with that PR was around its handling of URL dependencies,
so this PR _also_ refactors how we handle those. Previously, we stored
URL dependencies on `PubGrubPackage`, but they were omitted from the
hash and equality implementations of `PubGrubPackage`. This led to some
really careful codepaths wherein we had to ensure that we always visited
URLs before non-URL packages, so that the URL-inclusive versions were
included in any hashmaps, etc. I considered preserving this approach,
but it would require us to rely on lots of internal details of PubGrub
(since we'd now be relying on PubGrub to merge those packages in the
"right" order).
So, instead, we now _always_ set the URL on a given package, whenever
that package was _given_ a URL upfront. I think this is easier to reason
about: if the user provided a URL for `flask`, then we should just
always add the URL for `flask`. If we see some other URL for `flask`, we
error, like before. If we see some unknown URL for `flask`, we error,
like before.
Closes https://github.com/astral-sh/uv/issues/1522.
Closes https://github.com/astral-sh/uv/issues/1821.
Closes https://github.com/astral-sh/uv/issues/1615.
First, replace all usages in files in-place. I used my editor for this.
If someone wants to add a one-liner that'd be fun.
Then, update directory and file names:
```
# Run twice for nested directories
find . -type d -print0 | xargs -0 rename s/puffin/uv/g
find . -type d -print0 | xargs -0 rename s/puffin/uv/g
# Update files
find . -type f -print0 | xargs -0 rename s/puffin/uv/g
```
Then add all the files again
```
# Add all the files again
git add crates
git add python/uv
# This one needs a force-add
git add -f crates/uv-trampoline
```