feat: ability to install package subsets by tdejager · Pull Request #4404 · prefix-dev/pixi

tdejager · 2025-08-20T19:22:57Z

Overview

This Introduces install filtering to control what from the lockfile is installed. Adds new CLI options to skip packages, skip with full dependency subtree, or target a single package.

Why?

In some cases it might be desirable to skip part of the installation, e.g. for docker builds. Or you could be working on a pixi build project and only test part of the build changes. This unifies the behavior that was introduced with: #3092 by @olivier-lacroix

@ruben-arts noticed, that especially when also developing build backends it can be really annoying if you are only interested in a certain packages that it still tries to build others.

This kind of ties in with a new philosophy that we are trying out where we allow the user to play with the environment a bit more as long as you are able to recover.

When running these commands without --frozen, it can be the case that the lock file no longer reflects the environment changes.

CLI Changes

New pixi install options:
- --skip <NAME>: soft skip; omit package but still install its deps.
- --skip-with-deps <NAME>: hard skip; omit package and its dependency subtree unless reachable via another root.
- --package : install/build only the target package and its deps.

Some examples:

pixi install --skip foo
pixi install --skip-with-deps torch
pixi install --package numpy
Combine: pixi install --package app --skip-with-deps dev-docs --skip linters

How was this tested?

New Rust integration tests: tests/integration_rust/install_filter_tests.rs covering:
- soft skip, hard skip, target-only, combinations.

What was skipped.

PyPI filtering is unused until we implement ignore for the PyPI installer as well.

Notes for the reviewer

Core filtering:
- New InstallSubset in crates/pixi_core/src/lock_file/install_subset.rs builds a reachability graph over lockfile packages and applies:
- stop set: skip_with_deps
- passthrough set: skip (direct skip, traverse deps)
- optional target root: --only
Public API:
- InstallFilter in pixi_core::environment threads skip/target options through install/update paths.
- get_skipped_package_names to surface which packages were excluded.
Prefix updates:
- update_prefix filters lockfile packages before installing.
- Conda: passes ignored names to prefix updater to avoid installing skipped packages.

…s-with-deps

) Co-authored-by: Kilian Hu <kilian@hu101.com>

Co-authored-by: Tim de Jager <tim@prefix.dev> Co-authored-by: Ruben Arts <ruben.arts@hotmail.com>

Co-authored-by: Ruben Arts <ruben.arts@hotmail.com>

tdejager · 2025-08-28T10:25:50Z

Okay did a final user test myself on the ros_worskpace and fixed some annoyances that I encountered. Mainly with the messaging.

Things I added in the messaging:

--only filter
- “Installing foo in env bar, including 23 packages”
Few skips (<=5)
- “Installing … excluding 'a', 'b', 'c'”
Many skips (>5), with matched args
- “Installing … excluding 'a', 'b' and 17 other packages”
Many skips (>5), but none of the args are directly listed
- “Installing … excluding 19 other packages”
Unmatched skip args
- Warning: “The skipped arg(s) 'foo, bar' did not match any packages in the lock file”
No packages skipped
- “Installing … no packages were skipped (check if cli args were correct)”

tdejager · 2025-08-28T10:26:38Z

crates/pixi_cli/src/install.rs

+    pub only: Option<String>,
 }

+const SKIP_CUTOFF: usize = 5;


This just for the display method.

tdejager · 2025-08-28T10:26:48Z

crates/pixi_cli/src/install.rs

+    /// Skip a package and its entire dependency subtree. This performs a hard exclusion: the package and its dependencies are not installed unless reachable from another non-skipped root.
+    #[arg(long)]
+    pub skip_with_deps: Option<Vec<String>>,
+
+    /// Install and build only this package and its dependencies
+    #[arg(long)]
+    pub only: Option<String>,


Added these CLI args.

tdejager · 2025-08-28T10:27:04Z

crates/pixi_cli/src/install.rs

+    let filter = InstallFilter::new()
+        .skip_direct(args.skip.clone().unwrap_or_default())
+        .skip_with_deps(args.skip_with_deps.clone().unwrap_or_default())
+        .target_package(args.only.clone());


Here you see an example of setting an install filter.

tdejager · 2025-08-28T10:27:34Z

crates/pixi_cli/src/install.rs

            );
        }
+
+        if !all_skipped_packages.is_empty() {


This includes all the messaging, if we ever add the flag somewhere else we should consider reusing this.

tdejager · 2025-08-28T10:27:53Z

crates/pixi_command_dispatcher/src/install_pixi/mod.rs

            .with_download_client(command_dispatcher.download_client().clone())
            .with_package_cache(command_dispatcher.package_cache().clone())
            .with_reinstall_packages(self.force_reinstall)
+            .with_ignored_packages(self.ignore_packages.unwrap_or_default())


This is the new rattler feature that ignores installed packages.

tdejager · 2025-08-28T10:29:41Z

crates/pixi_core/src/lock_file/install_subset.rs

@@ -0,0 +1,458 @@
+use itertools::Itertools;


This the file that contains the graph reachability stuff and is kind of the meat of this feature.

tdejager · 2025-08-28T10:29:53Z

crates/pixi_core/src/lock_file/install_subset.rs

+    }
+}
+
+/// Filters packages using two skip modes and optional target selection.


Read this here carefully.

tdejager · 2025-08-28T10:30:10Z

crates/pixi_core/src/lock_file/install_subset.rs

+
+#[cfg(test)]
+mod tests {
+    use super::*;


I added simple unit tests to verify this behavior.

tdejager · 2025-08-28T10:31:51Z

crates/pixi_core/src/lock_file/update.rs

                    .partition::<Vec<_>, _>(|p| p.as_conda().is_some());

+                // TODO: use the same ignore logic for PyPI
+                let (ignored_conda, _ignored_pypi) = ignored


I've kept the behavior as before for PyPI. So that if you do:

pixi install --frozen --skip foobar`

It works like before, but we need to improve that, because without --frozen first this was required it might work unintuitively.

tdejager · 2025-08-28T10:33:28Z

tests/integration_rust/install_filter_tests.rs

@@ -0,0 +1,205 @@
+use pixi_core::{InstallFilter, UpdateLockFileOptions};


This contains some integration tests, with an e2e test to check if all works as expected.

tdejager

My own comments

ruben-arts · 2025-08-28T13:13:38Z

Found an easter egg:

> cd examples/pypi
> pixi i --only plot-antenna

✔ The default environment has been installed, including 70 packages excluding 18446744073709551591 other packages.

ruben-arts · 2025-08-28T13:14:34Z

I see only can't be defined multiple times, is there a technical reason for that?

ruben-arts · 2025-08-28T13:36:01Z

crates/pixi_core/src/lock_file/update.rs

                    .partition::<Vec<_>, _>(|p| p.as_conda().is_some());

+                // TODO: use the same ignore logic for PyPI
+                let (ignored_conda, _ignored_pypi) = ignored


Currently it also skips python if I do pixi install --only pypi-dependency since python is not a dependency. We need to always install python when we install only a pypi-dependency.

I just made all of this work.

crates/pixi_cli/src/install.rs

tdejager · 2025-08-29T12:27:12Z

I see only can't be defined multiple times, is there a technical reason for that?

There is, lets pick it up in a subsequent PR.

ruben-arts

Really cool! Thanks Tim

tdejager and others added 29 commits August 20, 2025 20:21

wip: working on creating package filtering

25b81d2

fix: fmt

f04d217

Merge branch 'main' into feat/install-build-partial-prefix

bc94ad6

wip: working on the algorithm a bit more

cce0806

fmt

95df5b8

fix: clippy warns

b60bcdc

fix: clippy

12bca8f

feat: finish data-structures for supporting --target, --skips, --skip…

f5b4e4e

…s-with-deps

feat: fix clippy

8e45893

feat: refactor a bit

d6e71bb

feat: integrate skipping throughout

e987718

fix: fmt

669df63

feat: fix install test

1a8fa98

fix: lint

07755c9

Merge branch 'main' into feat/install-build-partial-prefix

ceee459

Merge branch 'main' into feat/install-build-partial-prefix

6993dfa

fix: warn about no pinning strategy for unused features (prefix-dev#4065

29a720c

) Co-authored-by: Kilian Hu <kilian@hu101.com>

feat: update to latest rattler (prefix-dev#4422)

e721fe0

feat(cli): add new pixi global tree command (prefix-dev#4427)

aae6c25

Co-authored-by: Tim de Jager <tim@prefix.dev> Co-authored-by: Ruben Arts <ruben.arts@hotmail.com>

docs: Fix build getting started doc (prefix-dev#4415)

03d4c74

Co-authored-by: Ruben Arts <ruben.arts@hotmail.com>

feat: integrate with ignore

a2dce30

fix: clippy

86370c0

feat: update cli docs

7e21b99

feat: cli docs

5deca78

feat: install filter tests

995a612

feat: install filter tests

5728b91

fix: test message

433c693

feat: clippy fix

d062d6f

feat: clippy fix

236ffdc

tdejager changed the title ~~wip: working on creating package filtering~~ feat: working on creating package filtering Aug 26, 2025

tdejager requested a review from ruben-arts August 28, 2025 10:26

chore: rename function to better represent what it does

d9ecd7b

tdejager commented Aug 28, 2025

View reviewed changes

tdejager changed the title ~~feat: working on creating package filtering~~ feat: ability to install package subsets Aug 28, 2025

tdejager added 3 commits August 28, 2025 14:24

feat: install tests

d5941b8

feat: install tests

57a0be6

feat: install tests

aae596e

tdejager commented Aug 28, 2025

View reviewed changes

ruben-arts reviewed Aug 28, 2025

View reviewed changes

crates/pixi_cli/src/install.rs Outdated Show resolved Hide resolved

ruben-arts reviewed Aug 28, 2025

View reviewed changes

crates/pixi_cli/src/install.rs Outdated Show resolved Hide resolved

tdejager added 8 commits August 28, 2025 16:33

fix: fix diagnostics for single env

1d7e862

fix: fmt

2d854de

fix: fmt

70d35cc

fix: clippy

1af850e

feat:

08cd5af

fix: clippy

cb0c05a

Merge branch 'main' into feat/install-build-partial-prefix

a464dfa

feat: make pypi ignore logic as well

ef6ce9b

ruben-arts approved these changes Aug 29, 2025

View reviewed changes

ruben-arts merged commit 1721cc4 into prefix-dev:main Aug 29, 2025
42 checks passed

tdejager mentioned this pull request Sep 1, 2025

feat: add the option for multiple --only flags. #4477

Merged

BrewTestBot mentioned this pull request Sep 2, 2025

pixi 0.54.0 Homebrew/homebrew-core#235839

Merged

This was referenced Sep 11, 2025

Consider allow skipping install of specific package(s) #3182

Closed

feat(install): allow conda package subset selection (e.g. pixi i --skip) via manifest #4569

Open

varun-kht mentioned this pull request Feb 17, 2026

support --skip-with-deps/--skip for pixi global #5444

Open

		@@ -0,0 +1,205 @@
		use pixi_core::{InstallFilter, UpdateLockFileOptions};

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tdejager commented Aug 20, 2025 • edited by ruben-arts Loading Uh oh! There was an error while loading. Please reload this page.

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Overview

Why?

CLI Changes

Some examples:

How was this tested?

What was skipped.

Notes for the reviewer

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ruben-arts commented Aug 28, 2025

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tdejager commented Aug 20, 2025 •

edited by ruben-arts

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