Respect tool.uv.environments in pip compile --universal (#6663)

## Summary

We now respect the `environments` field in `uv pip compile --universal`,
e.g.:

```toml
[tool.uv]
environments = ["platform_system == 'Emscripten'"]
```

Closes https://github.com/astral-sh/uv/issues/6641.

crates/pypi-types/src/lib.rs

@@ -7,6 +7,7 @@ pub use parsed_url::*;
 pub use requirement::*;
 pub use scheme::*;
 pub use simple_json::*;
+pub use supported_environments::*;
 
 mod base_url;
 mod direct_url;
@@ -17,3 +18,4 @@ mod parsed_url;
 mod requirement;
 mod scheme;
 mod simple_json;
+mod supported_environments;

crates/pypi-types/src/supported_environments.rs

@@ -4,6 +4,7 @@ use serde::ser::SerializeSeq;
 
 use pep508_rs::MarkerTree;
 
+/// A list of supported marker environments.
 #[derive(Debug, Default, Clone, Eq, PartialEq)]
 pub struct SupportedEnvironments(Vec<MarkerTree>);
 

crates/uv-settings/src/combine.rs

@@ -3,6 +3,7 @@ use std::path::PathBuf;
 
 use distribution_types::IndexUrl;
 use install_wheel_rs::linker::LinkMode;
+use pypi_types::SupportedEnvironments;
 use uv_configuration::{ConfigSettings, IndexStrategy, KeyringProviderType, TargetTriple};
 use uv_python::{PythonDownloads, PythonPreference, PythonVersion};
 use uv_resolver::{AnnotationStyle, ExcludeNewer, PrereleaseMode, ResolutionMode};
@@ -75,12 +76,13 @@ impl_combine_or!(LinkMode);
 impl_combine_or!(NonZeroUsize);
 impl_combine_or!(PathBuf);
 impl_combine_or!(PrereleaseMode);
+impl_combine_or!(PythonDownloads);
+impl_combine_or!(PythonPreference);
 impl_combine_or!(PythonVersion);
 impl_combine_or!(ResolutionMode);
 impl_combine_or!(String);
+impl_combine_or!(SupportedEnvironments);
 impl_combine_or!(TargetTriple);
-impl_combine_or!(PythonPreference);
-impl_combine_or!(PythonDownloads);
 impl_combine_or!(bool);
 
 impl<T> Combine for Option<Vec<T>> {

crates/uv-settings/src/settings.rs

@@ -5,7 +5,7 @@ use serde::{Deserialize, Serialize};
 use distribution_types::{FlatIndexLocation, IndexUrl};
 use install_wheel_rs::linker::LinkMode;
 use pep508_rs::Requirement;
-use pypi_types::VerbatimParsedUrl;
+use pypi_types::{SupportedEnvironments, VerbatimParsedUrl};
 use uv_configuration::{
     ConfigSettings, IndexStrategy, KeyringProviderType, PackageNameSpecifier, TargetTriple,
 };
@@ -43,9 +43,15 @@ pub struct Options {
 
     // NOTE(charlie): These fields are shared with `ToolUv` in
     // `crates/uv-workspace/src/pyproject.rs`, and the documentation lives on that struct.
+    #[cfg_attr(feature = "schemars", schemars(skip))]
     pub override_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
+
+    #[cfg_attr(feature = "schemars", schemars(skip))]
     pub constraint_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
 
+    #[cfg_attr(feature = "schemars", schemars(skip))]
+    pub environments: Option<SupportedEnvironments>,
+
     // NOTE(charlie): These fields should be kept in-sync with `ToolUv` in
     // `crates/uv-workspace/src/pyproject.rs`.
     #[serde(default, skip_serializing)]
@@ -60,10 +66,6 @@ pub struct Options {
     #[cfg_attr(feature = "schemars", schemars(skip))]
     dev_dependencies: serde::de::IgnoredAny,
 
-    #[serde(default, skip_serializing)]
-    #[cfg_attr(feature = "schemars", schemars(skip))]
-    environments: serde::de::IgnoredAny,
-
     #[serde(default, skip_serializing)]
     #[cfg_attr(feature = "schemars", schemars(skip))]
     managed: serde::de::IgnoredAny,

crates/uv-workspace/src/lib.rs

@@ -1,10 +1,8 @@
-pub use environments::SupportedEnvironments;
 pub use workspace::{
     check_nested_workspaces, DiscoveryOptions, ProjectWorkspace, VirtualProject, Workspace,
     WorkspaceError, WorkspaceMember,
 };
 
-mod environments;
 pub mod pyproject;
 pub mod pyproject_mut;
 mod workspace;

crates/uv-workspace/src/pyproject.rs

@@ -14,9 +14,8 @@ use serde::{Deserialize, Serialize};
 use thiserror::Error;
 use url::Url;
 
-use crate::environments::SupportedEnvironments;
 use pep440_rs::VersionSpecifiers;
-use pypi_types::{RequirementSource, VerbatimParsedUrl};
+use pypi_types::{RequirementSource, SupportedEnvironments, VerbatimParsedUrl};
 use uv_git::GitReference;
 use uv_macros::OptionsMetadata;
 use uv_normalize::{ExtraName, PackageName};
@@ -121,11 +120,14 @@ pub struct ToolUv {
     /// By default, uv will resolve for all possible environments during a `uv lock` operation.
     /// However, you can restrict the set of supported environments to improve performance and avoid
     /// unsatisfiable branches in the solution space.
+    ///
+    /// These environments will also respected when `uv pip compile` is invoked with the
+    /// `--universal` flag.
     #[cfg_attr(
         feature = "schemars",
         schemars(
             with = "Option<Vec<String>>",
-            description = "A list of environment markers, e.g. `python_version >= '3.6'`."
+            description = "A list of environment markers, e.g., `python_version >= '3.6'`."
         )
     )]
     #[option(

crates/uv-workspace/src/workspace.rs

@@ -9,12 +9,11 @@ use rustc_hash::FxHashSet;
 use tracing::{debug, trace, warn};
 
 use pep508_rs::{MarkerTree, RequirementOrigin, VerbatimUrl};
-use pypi_types::{Requirement, RequirementSource, VerbatimParsedUrl};
+use pypi_types::{Requirement, RequirementSource, SupportedEnvironments, VerbatimParsedUrl};
 use uv_fs::Simplified;
 use uv_normalize::{GroupName, PackageName, DEV_DEPENDENCIES};
 use uv_warnings::warn_user;
 
-use crate::environments::SupportedEnvironments;
 use crate::pyproject::{Project, PyProjectToml, Source, ToolUvWorkspace};
 
 #[derive(thiserror::Error, Debug)]

crates/uv/src/commands/pip/compile.rs

@@ -11,7 +11,7 @@ use tracing::debug;
 
 use distribution_types::{IndexLocations, UnresolvedRequirementSpecification, Verbatim};
 use install_wheel_rs::linker::LinkMode;
-use pypi_types::Requirement;
+use pypi_types::{Requirement, SupportedEnvironments};
 use uv_auth::store_credentials_from_url;
 use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, Connectivity, FlatIndexClient, RegistryClientBuilder};
@@ -53,6 +53,7 @@ pub(crate) async fn pip_compile(
     build_constraints: &[RequirementsSource],
     constraints_from_workspace: Vec<Requirement>,
     overrides_from_workspace: Vec<Requirement>,
+    environments: SupportedEnvironments,
     extras: ExtrasSpecification,
     output_file: Option<&Path>,
     resolution_mode: ResolutionMode,
@@ -171,10 +172,10 @@ pub(crate) async fn pip_compile(
     }
 
     // Find an interpreter to use for building distributions
-    let environments = EnvironmentPreference::from_system_flag(system, false);
+    let environment_preference = EnvironmentPreference::from_system_flag(system, false);
     let interpreter = if let Some(python) = python.as_ref() {
         let request = PythonRequest::parse(python);
-        PythonInstallation::find(&request, environments, python_preference, &cache)
+        PythonInstallation::find(&request, environment_preference, python_preference, &cache)
     } else {
         // TODO(zanieb): The split here hints at a problem with the abstraction; we should be able to use
         // `PythonInstallation::find(...)` here.
@@ -184,7 +185,7 @@ pub(crate) async fn pip_compile(
         } else {
             PythonRequest::default()
         };
-        PythonInstallation::find_best(&request, environments, python_preference, &cache)
+        PythonInstallation::find_best(&request, environment_preference, python_preference, &cache)
     }?
     .into_interpreter();
 
@@ -244,7 +245,10 @@ pub(crate) async fn pip_compile(
 
     // Determine the environment for the resolution.
     let (tags, markers) = if universal {
-        (None, ResolverMarkers::universal(vec![]))
+        (
+            None,
+            ResolverMarkers::universal(environments.into_markers()),
+        )
     } else {
         let (tags, markers) =
             resolution_environment(python_version, python_platform, &interpreter)?;

crates/uv/src/commands/project/lock.rs

@@ -10,7 +10,7 @@ use tracing::debug;
 
 use distribution_types::{IndexLocations, UnresolvedRequirementSpecification};
 use pep440_rs::Version;
-use pypi_types::Requirement;
+use pypi_types::{Requirement, SupportedEnvironments};
 use uv_auth::store_credentials_from_url;
 use uv_cache::Cache;
 use uv_client::{Connectivity, FlatIndexClient, RegistryClientBuilder};
@@ -28,7 +28,7 @@ use uv_resolver::{
 };
 use uv_types::{BuildContext, BuildIsolation, EmptyInstalledPackages, HashStrategy};
 use uv_warnings::warn_user;
-use uv_workspace::{DiscoveryOptions, SupportedEnvironments, Workspace};
+use uv_workspace::{DiscoveryOptions, Workspace};
 
 use crate::commands::pip::loggers::{DefaultResolveLogger, ResolveLogger, SummaryResolveLogger};
 use crate::commands::project::{find_requires_python, FoundInterpreter, ProjectError, SharedState};

crates/uv/src/lib.rs

@@ -303,6 +303,7 @@ async fn run(cli: Cli) -> Result<ExitStatus> {
                 &build_constraints,
                 args.constraints_from_workspace,
                 args.overrides_from_workspace,
+                args.environments,
                 args.settings.extras,
                 args.settings.output_file.as_deref(),
                 args.settings.resolution,

crates/uv/src/settings.rs

@@ -7,7 +7,7 @@ use std::str::FromStr;
 use distribution_types::IndexLocations;
 use install_wheel_rs::linker::LinkMode;
 use pep508_rs::{ExtraName, RequirementOrigin};
-use pypi_types::Requirement;
+use pypi_types::{Requirement, SupportedEnvironments};
 use uv_cache::{CacheArgs, Refresh};
 use uv_cli::{
     options::{flag, resolver_installer_options, resolver_options},
@@ -927,9 +927,10 @@ pub(crate) struct PipCompileSettings {
     pub(crate) src_file: Vec<PathBuf>,
     pub(crate) constraint: Vec<PathBuf>,
     pub(crate) r#override: Vec<PathBuf>,
+    pub(crate) build_constraint: Vec<PathBuf>,
     pub(crate) constraints_from_workspace: Vec<Requirement>,
     pub(crate) overrides_from_workspace: Vec<Requirement>,
-    pub(crate) build_constraint: Vec<PathBuf>,
+    pub(crate) environments: SupportedEnvironments,
     pub(crate) refresh: Refresh,
     pub(crate) settings: PipSettings,
 }
@@ -1015,6 +1016,12 @@ impl PipCompileSettings {
             Vec::new()
         };
 
+        let environments = if let Some(configuration) = &filesystem {
+            configuration.environments.clone().unwrap_or_default()
+        } else {
+            SupportedEnvironments::default()
+        };
+
         Self {
             src_file,
             constraint: constraint
@@ -1031,6 +1038,7 @@ impl PipCompileSettings {
                 .collect(),
             constraints_from_workspace,
             overrides_from_workspace,
+            environments,
             refresh: Refresh::from(refresh),
             settings: PipSettings::combine(
                 PipOptions {

crates/uv/tests/pip_compile.rs

@@ -11946,3 +11946,52 @@ fn symlink() -> Result<()> {
 
     Ok(())
 }
+
+/// Resolve with `--universal`, applying user-provided constraints to the space of supported
+/// environments.
+#[test]
+fn universal_constrained_environment() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["black"]
+
+        [tool.uv]
+        environments = "platform_system != 'Windows'"
+        "#,
+    )?;
+
+    uv_snapshot!(context.filters(), context.pip_compile()
+    .arg("pyproject.toml")
+    .arg("--universal"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] pyproject.toml --universal
+    black==24.3.0 ; platform_system != 'Windows'
+        # via project (pyproject.toml)
+    click==8.1.7 ; platform_system != 'Windows'
+        # via black
+    mypy-extensions==1.0.0 ; platform_system != 'Windows'
+        # via black
+    packaging==24.0 ; platform_system != 'Windows'
+        # via black
+    pathspec==0.12.1 ; platform_system != 'Windows'
+        # via black
+    platformdirs==4.2.0 ; platform_system != 'Windows'
+        # via black
+
+    ----- stderr -----
+    Resolved 6 packages in [TIME]
+    "###
+    );
+
+    Ok(())
+}

crates/uv/tests/show_settings.rs

@@ -76,9 +76,12 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -211,9 +214,12 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -347,9 +353,12 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -515,9 +524,12 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -652,9 +664,12 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -775,9 +790,12 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -935,9 +953,12 @@ fn resolve_index_url() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -1095,9 +1116,12 @@ fn resolve_index_url() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -1300,9 +1324,12 @@ fn resolve_find_links() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -1459,9 +1486,12 @@ fn resolve_top_level() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -1588,9 +1618,12 @@ fn resolve_top_level() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -1745,9 +1778,12 @@ fn resolve_top_level() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -1926,9 +1962,12 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -2045,9 +2084,12 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -2164,9 +2206,12 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -2285,9 +2330,12 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -2576,9 +2624,12 @@ fn resolve_poetry_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -2723,9 +2774,12 @@ fn resolve_both() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -2885,9 +2939,12 @@ fn resolve_config_file() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -3122,9 +3179,12 @@ fn resolve_skip_empty() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {
@@ -3244,9 +3304,12 @@ fn resolve_skip_empty() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        build_constraint: [],
         constraints_from_workspace: [],
         overrides_from_workspace: [],
-        build_constraint: [],
+        environments: SupportedEnvironments(
+            [],
+        ),
         refresh: None(
             Timestamp(
                 SystemTime {

docs/reference/settings.md

@@ -243,6 +243,9 @@ By default, uv will resolve for all possible environments during a `uv lock` ope
 However, you can restrict the set of supported environments to improve performance and avoid
 unsatisfiable branches in the solution space.
 
+These environments will also respected when `uv pip compile` is invoked with the
+`--universal` flag.
+
 **Default value**: `[]`
 
 **Type**: `str | list[str]`

uv.schema.json

@@ -77,7 +77,7 @@
       }
     },
     "environments": {
-      "description": "A list of environment markers, e.g. `python_version >= '3.6'`.",
+      "description": "A list of environment markers, e.g., `python_version >= '3.6'`.",
       "type": [
         "array",
         "null"