feat: use python_site_packages_path field when available for installing noarch: python packages, CEP-17

crates/rattler/src/install/python.rs

@@ -28,10 +28,10 @@
     InvalidVersion(String),
 }
 
 impl PythonInfo {
     /// Build an instance based on the version of the python package and the platform it is
     /// installed for.
-    pub fn from_version(version: &Version, platform: Platform) -> Result<Self, PythonInfoError> {
+    pub fn from_version(version: &Version, sp_path: &Option<String>, platform: Platform) -> Result<Self, PythonInfoError> {
         // Determine the major, and minor versions of the version
         let (major, minor) = version
             .as_major_minor()
@@ -44,11 +44,14 @@
             PathBuf::from(format!("bin/python{major}.{minor}"))
         };
 
         // Find the location of the site packages
-        let site_packages_path = if platform.is_windows() {
-            PathBuf::from("Lib/site-packages")
-        } else {
-            PathBuf::from(format!("lib/python{major}.{minor}/site-packages"))
+        let site_packages_path = match sp_path {
+            Some(sp_path) => PathBuf::from(sp_path),
+            None => if platform.is_windows() {
+                        PathBuf::from("Lib/site-packages")
+                    } else {
+                    PathBuf::from(format!("lib/python{major}.{minor}/site-packages"))
+            },
         };
 
         // Binary directory

crates/rattler/src/install/transaction.rs

@@ -196,10 +196,10 @@
     records: impl IntoIterator<Item = impl AsRef<PackageRecord>>,
     platform: Platform,
 ) -> Result<Option<PythonInfo>, PythonInfoError> {
     records
         .into_iter()
         .find(|r| is_python_record(r.as_ref()))
-        .map(|record| PythonInfo::from_version(&record.as_ref().version, platform))
+        .map(|record| PythonInfo::from_version(&record.as_ref().version, &record.as_ref().python_site_packages_path, platform))
         .map_or(Ok(None), |info| info.map(Some))
 }
 

crates/rattler_conda_types/src/package/index.rs

@@ -55,6 +55,9 @@ pub struct IndexJson {
     /// Optionally, the OS the package is build for.
     pub platform: Option<String>,
 
+    /// Optionally a path within the environment of the site-packages directory
+    pub python_site_packages_path: Option<String>,
+
     /// The subdirectory that contains this package
     pub subdir: Option<String>,
 

crates/rattler_conda_types/src/repo_data/mod.rs

@@ -151,6 +151,9 @@ pub struct PackageRecord {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub purls: Option<BTreeSet<PackageUrl>>,
 
+    /// Optionally a path within the environment of the site-packages directory
+    pub python_site_packages_path: Option<String>,
+
     /// Run exports that are specified in the package.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub run_exports: Option<RunExportsJson>,
@@ -294,6 +297,7 @@ impl PackageRecord {
             name,
             noarch: NoArchType::default(),
             platform: None,
+            python_site_packages_path: None,
             sha256: None,
             size: None,
             subdir: Platform::current().to_string(),
@@ -412,6 +416,7 @@ impl PackageRecord {
             name: index.name,
             noarch: index.noarch,
             platform: index.platform,
+            python_site_packages_path: index.python_site_packages_path,
             sha256,
             size,
             subdir,