uv/crates
konsti 431ddc1d74
Change backtracking when packages conflict too much (#9843)
Background reading: https://github.com/astral-sh/uv/issues/8157
Companion PR: https://github.com/astral-sh/pubgrub/pull/36
Requires for test coverage: https://github.com/astral-sh/packse/pull/230

When two packages A and B conflict, we have the option to choose a lower
version of A, or a lower version of B. Currently, we determine this by
the order we saw a package (assuming equal specificity of the
requirement): If we saw A before B, we pin A until all versions of B are
exhausted. This can lead to undesirable outcomes, from cases where it's
just slow (sentry) to others cases without lower bounds where be
backtrack to a very old version of B. This old version may fail to build
(terminating the resolution), or it's a version so old that it doesn't
depend on A (or the shared conflicting package) anymore - but also is
too old for the user's application (fastapi). #8157 collects such cases,
and the `wrong-backtracking` packse scenario contains a minimized
example.

We try to solve this by tracking which packages are "A"s, culprits, and
"B"s, affected, and manually interfering with project selection and
backtracking. Whenever a version we just chose is rejected, we give the
current package a counter for being affected, and the package it
conflicted with a counter for being a culprit. If a package accumulates
more counts than a threshold, we reprioritize: Undecided after the
culprits, after the affected, after packages that only have a single
version (URLs, `==<version>`). We then ask pubgrub to backtrack just
before the culprit. Due to the changed priorities, we now select package
B, the affected, instead of package A, the culprit.

To do this efficiently, we ask pubgrub for the incompatibility that
caused backtracking, or just the last version to be discarded (due to
its dependencies). For backtracking, we use the last incompatibility
from unit propagation as a heuristic. When a version is discarded
because one of its dependencies conflicts with the partial solution, the
incompatibility tells us the package in the partial solution that
conflicted.

We only backtrack once per package, on the first time it passes the
threshold. This prevents backtracking loops in which we make the same
decisions over and over again. But we also changed the priority, so that
we shouldn't take the same path even after the one time we backtrack (it
would defeat the purpose of this change).

There are some parameters that can be tweaked: Currently, the threshold
is set to 5, which feels not too eager with so me of the conflicts that
we want to tolerate but also changes strategies quickly. The relative
order of the new priorities can also be changed, as for each (A, B) pair
the priority of B is afterwards lower than that for A. Currently,
culprits capture conflict for the whole package, but we could limit that
to a specific version. We could discard conflict counters after
backtracking instead of keeping them eternally as we do now. Note that
we're always taking about pairs (A, B), but in practice we track
individual packages, not pairs.

A case that we wouldn't capture is when B is only introduced to the
dependency graph after A, but I think that would require cyclical
dependency for A and B to conflict? There may also be cases where
looking at the last incompatibility is insufficient.

Another example that we can't repair with prioritization is
urllib3/boto3/botocore: We actually have to check all the newer versions
of boto3 and botocore to identify the version that allows with the older
urllib3, no shortcuts allowed.

```
urllib3<1.25.4
boto3
```

All examples I tested were cases with two packages where we only had to
switch the order, so I've abstracted them into a single packse case.

This PR changes the resolution for certain paths, and there is the risk
for regressions.

Fixes #8157

---

All tested examples improved.

Input fastapi:
```text
starlette<=0.36.0
fastapi<=0.115.2
```

```
# BEFORE
$ uv pip --no-progress compile -p 3.11 --exclude-newer 2024-10-01 --no-annotate debug/fastapi.txt
annotated-types==0.7.0
anyio==4.6.0
fastapi==0.1.17
idna==3.10
pydantic==2.9.2
pydantic-core==2.23.4
sniffio==1.3.1
starlette==0.36.0
typing-extensions==4.12.2

# AFTER
$ cargo run --profile fast-build --no-default-features pip compile -p 3.11 --no-progress --exclude-newer 2024-10-01 --no-annotate debug/fastapi.txt 
annotated-types==0.7.0
anyio==4.6.0
fastapi==0.109.1
idna==3.10
pydantic==2.9.2
pydantic-core==2.23.4
sniffio==1.3.1
starlette==0.35.1
typing-extensions==4.12.2
```


Input xarray:
```text
xarray[accel]
```

```
# BEFORE
$ uv pip --no-progress compile -p 3.11 --exclude-newer 2024-10-01 --no-annotate debug/xarray-accel.txt
bottleneck==1.4.0
flox==0.9.13
llvmlite==0.36.0
numba==0.53.1
numbagg==0.8.2
numpy==2.1.1
numpy-groupies==0.11.2
opt-einsum==3.4.0
packaging==24.1
pandas==2.2.3
python-dateutil==2.9.0.post0
pytz==2024.2
scipy==1.14.1
setuptools==75.1.0
six==1.16.0
toolz==0.12.1
tzdata==2024.2
xarray==2024.9.0

# AFTER
$ cargo run --profile fast-build --no-default-features pip compile -p 3.11 --no-progress --exclude-newer 2024-10-01 --no-annotate debug/xarray-accel.txt
bottleneck==1.4.0
flox==0.9.13
llvmlite==0.43.0
numba==0.60.0
numbagg==0.8.2
numpy==2.0.2
numpy-groupies==0.11.2
opt-einsum==3.4.0
packaging==24.1
pandas==2.2.3
python-dateutil==2.9.0.post0
pytz==2024.2
scipy==1.14.1
six==1.16.0
toolz==0.12.1
tzdata==2024.2
xarray==2024.9.0
```


Input sentry: The resolution is identical, but arrived at much faster:
main tries 69 versions (sentry-kafka-schemas: 63), PR tries 12 versions
(sentry-kafka-schemas: 6; 5 times conflicting, then once the right
version).

```text
python-rapidjson<=1.20,>=1.4
sentry-kafka-schemas<=0.1.113,>=0.1.50
```

```
# BEFORE
$ uv pip --no-progress compile -p 3.11 --exclude-newer 2024-10-01 --no-annotate debug/sentry.txt
fastjsonschema==2.20.0
msgpack==1.1.0
python-rapidjson==1.8
pyyaml==6.0.2
sentry-kafka-schemas==0.1.111
typing-extensions==4.12.2

# AFTER
$ cargo run --profile fast-build --no-default-features pip compile -p 3.11 --no-progress --exclude-newer 2024-10-01 --no-annotate debug/sentry.txt
fastjsonschema==2.20.0
msgpack==1.1.0
python-rapidjson==1.8
pyyaml==6.0.2
sentry-kafka-schemas==0.1.111
typing-extensions==4.12.2
```


Input apache-beam
```text
# Run on Python 3.10
dill<0.3.9,>=0.2.2
apache-beam<=2.49.0
```

```
# BEFORE
$ uv pip --no-progress compile -p 3.10 --exclude-newer 2024-10-01 --no-annotate debug/apache-beam.txt
  × Failed to download and build `apache-beam==2.0.0`
  ╰─▶ Build backend failed to determine requirements with `build_wheel()` (exit status: 1)

# AFTER
$ cargo run --profile fast-build --no-default-features pip compile -p 3.10 --no-progress --exclude-newer 2024-10-01 --no-annotate debug/apache-beam.txt
apache-beam==2.49.0
certifi==2024.8.30
charset-normalizer==3.3.2
cloudpickle==2.2.1
crcmod==1.7
dill==0.3.1.1
dnspython==2.6.1
docopt==0.6.2
fastavro==1.9.7
fasteners==0.19
grpcio==1.66.2
hdfs==2.7.3
httplib2==0.22.0
idna==3.10
numpy==1.24.4
objsize==0.6.1
orjson==3.10.7
proto-plus==1.24.0
protobuf==4.23.4
pyarrow==11.0.0
pydot==1.4.2
pymongo==4.10.0
pyparsing==3.1.4
python-dateutil==2.9.0.post0
pytz==2024.2
regex==2024.9.11
requests==2.32.3
six==1.16.0
typing-extensions==4.12.2
urllib3==2.2.3
zstandard==0.23.0
```
2024-12-16 11:39:50 +01:00
..
uv Change backtracking when packages conflict too much (#9843) 2024-12-16 11:39:50 +01:00
uv-auth Publish: Warn when keyring has no password (#8827) 2024-11-27 20:54:49 +01:00
uv-bench Build backend: Add direct builds to the resolver and installer (#9621) 2024-12-04 15:57:18 +00:00
uv-build-backend Allow underscores in entrypoints (#9825) 2024-12-11 22:24:18 +00:00
uv-build-frontend Build backend: Add direct builds to the resolver and installer (#9621) 2024-12-04 15:57:18 +00:00
uv-cache Avoid reusing interpreter metadata when running under Rosetta (#9846) 2024-12-12 13:21:35 -05:00
uv-cache-info Improve error message for cache info serialization (#8500) 2024-10-23 13:17:31 +00:00
uv-cache-key Remove separate test files in favor of same-file `mod tests` (#9199) 2024-11-18 20:11:46 +00:00
uv-cli Document the `--fork-strategy` setting (#9887) 2024-12-13 21:35:20 +00:00
uv-client Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-configuration Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-console Support interactive input in `uv publish` (#8158) 2024-10-15 10:00:43 +02:00
uv-dev Build backend: Add template to uv init (#9661) 2024-12-05 15:30:48 +01:00
uv-dirs Eliminate dependencies on `directores` and `dirs-sys` (#8048) 2024-11-07 14:29:54 -06:00
uv-dispatch Remove derivation chain special casing (#9678) 2024-12-06 13:05:03 +00:00
uv-distribution Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-distribution-filename Add test coverage for build tag prioritization (#9680) 2024-12-06 09:32:19 -05:00
uv-distribution-types Fork version selection based on `requires-python` requirements (#9827) 2024-12-13 15:33:46 -05:00
uv-extract Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-fs Avoid `panic!()` when current directory does not exist (#9876) 2024-12-13 21:39:46 +00:00
uv-git Remove separate test files in favor of same-file `mod tests` (#9199) 2024-11-18 20:11:46 +00:00
uv-globfilter Build backend: Revamp include/exclude (#9525) 2024-12-01 11:32:35 +00:00
uv-install-wheel Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-installer Refactor unavailable metadata to shrink the resolver (#9769) 2024-12-10 16:46:53 +00:00
uv-macros Generate environment variables doc from code (#8493) 2024-11-03 08:31:38 -06:00
uv-metadata chore: Move all integration tests to a single binary (#8093) 2024-10-11 16:41:35 +02:00
uv-normalize Remove separate test files in favor of same-file `mod tests` (#9199) 2024-11-18 20:11:46 +00:00
uv-once-map Use shared resolver state between add and lock (#8146) 2024-10-12 14:58:07 +00:00
uv-options-metadata Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-pep440 Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-pep508 Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-performance-flate2-backend Use `zlib-rs` on all platforms (#9264) 2024-11-20 00:01:58 -05:00
uv-performance-memory-allocator Run `cargo update` (#8703) 2024-11-01 10:26:21 -04:00
uv-platform-tags Fix Python interpreter discovery on non-glibc hosts (#9005) 2024-11-21 12:35:02 +01:00
uv-publish Upload: All metadata incl. PEP 639 (#9442) 2024-11-27 00:25:08 +01:00
uv-pypi-types Show a concise error message for missing version field (#9912) 2024-12-15 10:27:43 -05:00
uv-python Patch additional `sysconfig` values such as AR at install time (#9905) 2024-12-15 10:27:54 -05:00
uv-requirements Eagerly error when parsing `pyproject.toml` requirements (#9704) 2024-12-07 14:14:26 +00:00
uv-requirements-txt Align `indoc` and `base64` workspace dependencies with root project (#9555) 2024-12-01 17:20:22 -05:00
uv-resolver Change backtracking when packages conflict too much (#9843) 2024-12-16 11:39:50 +01:00
uv-scripts Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-settings Document the `--fork-strategy` setting (#9887) 2024-12-13 21:35:20 +00:00
uv-shell Refactor shell quoting (#9055) 2024-11-15 09:06:54 +00:00
uv-state Add `uv-dirs` to consolidate directory lookup methods (#8453) 2024-10-22 11:33:25 -05:00
uv-static Introduce a `--fork-strategy` preference mode (#9868) 2024-12-13 16:05:07 -05:00
uv-tool Enable `uv tool uninstall uv` on Windows (#8963) 2024-12-10 13:13:22 -05:00
uv-trampoline Update Rust crate thiserror to v2.0.7 (#9926) 2024-12-15 20:12:08 -05:00
uv-trampoline-builder Add support for installing versioned Python executables on Windows (#8663) 2024-10-31 15:58:35 +00:00
uv-types Upgrade minimum Rust version to 1.83 (#9815) 2024-12-11 10:06:19 -06:00
uv-version Bump version to v0.5.9 (#9889) 2024-12-13 17:28:19 -05:00
uv-virtualenv Patch `sysconfig` data at install time (#9857) 2024-12-13 14:36:22 -05:00
uv-warnings chore: Move all integration tests to a single binary (#8093) 2024-10-11 16:41:35 +02:00
uv-workspace Show a concise error message for missing version field (#9912) 2024-12-15 10:27:43 -05:00
README.md Link to Dependency specifiers instead of PEP 508 (#8411) 2024-10-21 14:43:38 -04:00

README.md

Crates

uv-bench

Functionality for benchmarking uv.

uv-cache-key

Generic functionality for caching paths, URLs, and other resources across platforms.

uv-distribution-filename

Parse built distribution (wheel) and source distribution (sdist) filenames to extract structured metadata.

uv-distribution-types

Abstractions for representing built distributions (wheels) and source distributions (sdists), and the sources from which they can be downloaded.

uv-install-wheel-rs

Install built distributions (wheels) into a virtual environment.

uv-once-map

A waitmap-like concurrent hash map for executing tasks exactly once.

uv-pep440-rs

Utilities for interacting with Python version numbers and specifiers.

uv-pep508-rs

Utilities for parsing and evaluating dependency specifiers, previously known as PEP 508.

uv-platform-tags

Functionality for parsing and inferring Python platform tags as per PEP 425.

uv-cli

Command-line interface for the uv package manager.

uv-build-frontend

A PEP 517-compatible build frontend for uv.

uv-cache

Functionality for caching Python packages and associated metadata.

uv-client

Client for interacting with PyPI-compatible HTTP APIs.

uv-dev

Development utilities for uv.

uv-dispatch

A centralized struct for resolving and building source distributions in isolated environments. Implements the traits defined in uv-types.

uv-distribution

Client for interacting with built distributions (wheels) and source distributions (sdists). Capable of fetching metadata, distribution contents, etc.

uv-extract

Utilities for extracting files from archives.

uv-fs

Utilities for interacting with the filesystem.

uv-git

Functionality for interacting with Git repositories.

uv-installer

Functionality for installing Python packages into a virtual environment.

uv-python

Functionality for detecting and leveraging the current Python interpreter.

uv-normalize

Normalize package and extra names as per Python specifications.

uv-requirements

Utilities for reading package requirements from pyproject.toml and requirements.txt files.

uv-resolver

Functionality for resolving Python packages and their dependencies.

uv-shell

Utilities for detecting and manipulating shell environments.

uv-types

Shared traits for uv, to avoid circular dependencies.

uv-pypi-types

General-purpose type definitions for types used in PyPI-compatible APIs.

uv-virtualenv

A venv replacement to create virtual environments in Rust.

uv-warnings

User-facing warnings for uv.

uv-workspace

Workspace abstractions for uv.

uv-requirements-txt

Functionality for parsing requirements.txt files.