refactor: BREAKING: make name optional

crates/pixi_build_frontend/src/backend/in_memory/passthrough.rs

@@ -13,7 +13,7 @@ use pixi_build_types::{
         initialize::InitializeParams,
     },
 };
-use rattler_conda_types::{Platform, Version, package::IndexJson};
+use rattler_conda_types::{PackageName, Platform, Version, package::IndexJson};
 use serde::Deserialize;
 
 use crate::{
@@ -64,7 +64,19 @@ impl InMemoryBackend for PassthroughBackend {
         Ok(CondaOutputsResult {
             outputs: vec![CondaOutput {
                 metadata: CondaOutputMetadata {
-                    name: self.project_model.name.parse().unwrap(),
+                    name: self
+                        .project_model
+                        .name
+                        .as_ref()
+                        .map(|name| PackageName::try_from(name.as_str()).unwrap())
+                        .unwrap_or_else(|| {
+                            self.index_json
+                                .as_ref()
+                                .map(|j| j.name.clone())
+                                .unwrap_or_else(|| {
+                                    PackageName::try_from("pixi-package_name").unwrap()
+                                })
+                        }),
                     version: self
                         .project_model
                         .version

crates/pixi_build_type_conversions/src/project_model.rs

@@ -173,7 +173,7 @@ pub fn to_project_model_v1(
 ) -> Result<pbt::ProjectModelV1, SpecConversionError> {
     let project = pbt::ProjectModelV1 {
         name: manifest.package.name.clone(),
-        version: Some(manifest.package.version.clone()),
+        version: manifest.package.version.clone(),
         description: manifest.package.description.clone(),
         authors: manifest.package.authors.clone(),
         license: manifest.package.license.clone(),

crates/pixi_build_types/src/lib.rs

@@ -23,13 +23,17 @@ use rattler_conda_types::{
 };
 use serde::{Deserialize, Serialize};
 
+// Version 0: Initial version
+// Version 1: Added conda/outputs and conda/build_v1
+// Version 2: Name in project models can be `None`.
+
 /// The constraint for the pixi build api version package
 /// Adding this constraint when solving a pixi build backend environment ensures
 /// that a backend is selected that uses the same interface version as Pixi does
 pub static PIXI_BUILD_API_VERSION_NAME: LazyLock<PackageName> =
     LazyLock::new(|| PackageName::new_unchecked("pixi-build-api-version"));
 pub const PIXI_BUILD_API_VERSION_LOWER: u64 = 0;
-pub const PIXI_BUILD_API_VERSION_CURRENT: u64 = 1;
+pub const PIXI_BUILD_API_VERSION_CURRENT: u64 = 2;
 pub const PIXI_BUILD_API_VERSION_UPPER: u64 = PIXI_BUILD_API_VERSION_CURRENT + 1;
 pub static PIXI_BUILD_API_VERSION_SPEC: LazyLock<VersionSpec> = LazyLock::new(|| {
     VersionSpec::Group(
@@ -85,9 +89,17 @@ impl PixiBuildApiVersion {
                 provides_conda_build_v1: Some(true),
                 ..Self(0).expected_backend_capabilities()
             },
+            2 => BackendCapabilities {
+                ..Self(1).expected_backend_capabilities()
+            },
             _ => BackendCapabilities::default(),
         }
     }
+
+    /// Returns true if this version of the protocol supports the name field in the project model to be `None`.
+    pub fn supports_name_none(&self) -> bool {
+        self.0 >= 2
+    }
 }
 
 impl Display for PixiBuildApiVersion {

crates/pixi_build_types/src/project_model.rs

@@ -74,7 +74,7 @@ pub type SourcePackageName = String;
 #[serde(rename_all = "camelCase")]
 pub struct ProjectModelV1 {
     /// The name of the project
-    pub name: String,
+    pub name: Option<String>,
 
     /// The version of the project
     pub version: Option<Version>,
@@ -176,17 +176,18 @@ impl TargetsV1 {
 }
 
 impl IsDefault for TargetsV1 {
-    fn is_default(&self) -> bool {
-        self.is_empty()
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        if !self.is_empty() { Some(self) } else { None }
     }
 }
 
 impl<T: IsDefault> IsDefault for Option<T> {
-    fn is_default(&self) -> bool {
-        match self {
-            None => true,
-            Some(value) => value.is_default(),
-        }
+    type Item = T::Item;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        self.as_ref()?.is_non_default()
     }
 }
 
@@ -219,8 +220,10 @@ impl TargetV1 {
 }
 
 impl IsDefault for TargetV1 {
-    fn is_default(&self) -> bool {
-        self.is_empty()
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        if !self.is_empty() { Some(self) } else { None }
     }
 }
 
@@ -601,8 +604,10 @@ impl Hash for GitReferenceV1 {
 }
 
 impl IsDefault for GitReferenceV1 {
-    fn is_default(&self) -> bool {
-        false // Never skip GitReferenceV1 fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip GitReferenceV1 fields
     }
 }
 
@@ -642,7 +647,7 @@ mod tests {
     fn test_hash_stability_with_default_values() {
         // Create a minimal ProjectModelV1 instance
         let mut project_model = ProjectModelV1 {
-            name: "test-project".to_string(),
+            name: Some("test-project".to_string()),
             version: None,
             description: None,
             authors: None,
@@ -698,7 +703,7 @@ mod tests {
     fn test_hash_changes_with_meaningful_values() {
         // Create a minimal ProjectModelV1 instance
         let mut project_model = ProjectModelV1 {
-            name: "test-project".to_string(),
+            name: Some("test-project".to_string()),
             version: None,
             description: None,
             authors: None,
@@ -993,14 +998,14 @@ mod tests {
     fn test_hash_collision_bug_project_model() {
         // Test the same issue in ProjectModelV1
         let project1 = ProjectModelV1 {
-            name: "test".to_string(),
+            name: Some("test".to_string()),
             description: Some("test description".to_string()),
             license: None,
             ..Default::default()
         };
 
         let project2 = ProjectModelV1 {
-            name: "test".to_string(),
+            name: Some("test".to_string()),
             description: None,
             license: Some("test description".to_string()),
             ..Default::default()

crates/pixi_build_types/src/stable_hash.rs

@@ -35,7 +35,9 @@ impl Hash for FieldDiscriminant {
 /// Trait to determine if a value should be considered "default" and thus skipped in hash calculations.
 /// This helps maintain forward/backward compatibility by only including discriminants for meaningful values.
 pub(crate) trait IsDefault {
-    fn is_default(&self) -> bool;
+    type Item;
+
+    fn is_non_default(&self) -> Option<&Self::Item>;
 }
 
 /// A dyn-compatible hashing trait that works with any hasher type
@@ -66,9 +68,12 @@ impl<'a, H: std::hash::Hasher> StableHashBuilder<'a, H> {
 
     /// Add a field to the hash if it's not in its default state.
     /// Fields will be automatically sorted alphabetically before hashing.
-    pub fn field<T: Hash + IsDefault>(mut self, name: &'static str, value: &'a T) -> Self {
-        if !value.is_default() {
-            self.fields.insert(name, value);
+    pub fn field<T: IsDefault>(mut self, name: &'static str, value: &'a T) -> Self
+    where
+        T::Item: Hash,
+    {
+        if let Some(item) = value.is_non_default() {
+            self.fields.insert(name, item);
         }
         self
     }
@@ -83,61 +88,81 @@ impl<'a, H: std::hash::Hasher> StableHashBuilder<'a, H> {
 }
 
 impl<K, V> IsDefault for OrderMap<K, V> {
-    fn is_default(&self) -> bool {
-        self.is_empty()
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        if !self.is_empty() { Some(self) } else { None }
     }
 }
 
 impl IsDefault for String {
-    fn is_default(&self) -> bool {
-        false // Never skip required string fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip required string fields
     }
 }
 
 impl IsDefault for url::Url {
-    fn is_default(&self) -> bool {
-        false // Never skip required URL fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip required URL fields
     }
 }
 
 impl IsDefault for std::path::PathBuf {
-    fn is_default(&self) -> bool {
-        false // Never skip PathBuf fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip PathBuf fields
     }
 }
 
 impl<T> IsDefault for Vec<T> {
-    fn is_default(&self) -> bool {
-        self.is_empty()
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        if !self.is_empty() { Some(self) } else { None }
     }
 }
 
 impl IsDefault for rattler_conda_types::Version {
-    fn is_default(&self) -> bool {
-        false // Never skip version fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip version fields
     }
 }
 
 impl IsDefault for rattler_conda_types::StringMatcher {
-    fn is_default(&self) -> bool {
-        false // Never skip StringMatcher fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip StringMatcher fields
     }
 }
 
 impl IsDefault for rattler_conda_types::BuildNumberSpec {
-    fn is_default(&self) -> bool {
-        false // Never skip BuildNumberSpec fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip BuildNumberSpec fields
     }
 }
 
 impl IsDefault for rattler_conda_types::VersionSpec {
-    fn is_default(&self) -> bool {
-        false // Never skip VersionSpec fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip VersionSpec fields
     }
 }
 
 impl<U, T: rattler_digest::digest::generic_array::ArrayLength<U>> IsDefault for GenericArray<U, T> {
-    fn is_default(&self) -> bool {
-        false // Never skip digest output fields
+    type Item = Self;
+
+    fn is_non_default(&self) -> Option<&Self::Item> {
+        Some(self) // Never skip digest output fields
     }
 }

crates/pixi_command_dispatcher/src/command_dispatcher/instantiate_backend.rs

@@ -151,6 +151,19 @@ impl CommandDispatcher {
             api_version,
         );
 
+        // Make sure that the project model is compatible with the API version.
+        if !api_version.supports_name_none()
+            && spec
+                .init_params
+                .project_model
+                .as_ref()
+                .is_some_and(|p| p.name.is_none())
+        {
+            return Err(CommandDispatcherError::Failed(
+                InstantiateBackendError::SpecConversionError(SpecConversionError::MissingName),
+            ));
+        }
+
         JsonRpcBackend::setup(
             source_dir,
             spec.init_params.manifest_path,

crates/pixi_core/src/lock_file/satisfiability/mod.rs

@@ -1142,6 +1142,9 @@ pub(crate) async fn verify_package_platform_satisfiability(
                                         ParseChannelError::InvalidPath(p).into()
                                     }
                                     SpecConversionError::InvalidChannel(_name, p) => p.into(),
+                                    SpecConversionError::MissingName => {
+                                        ParseMatchSpecError::MissingPackageName
+                                    }
                                 };
                                 return Err(Box::new(PlatformUnsat::FailedToParseMatchSpec(
                                     name.as_source().to_string(),
@@ -1951,7 +1954,6 @@ mod tests {
 
     #[rstest]
     #[tokio::test]
-    #[cfg_attr(not(feature = "slow_integration_tests"), ignore)]
     async fn test_example_satisfiability(
         #[files("../../examples/**/p*.toml")] manifest_path: PathBuf,
     ) {

crates/pixi_core/src/lock_file/satisfiability/snapshots/pixi_core__lock_file__satisfiability__tests__failing_satisiability@source-dependency-changed-project-model.snap

@@ -1,7 +1,8 @@
 ---
-source: src/lock_file/satisfiability/mod.rs
+source: crates/pixi_core/src/lock_file/satisfiability/mod.rs
 expression: s
+snapshot_kind: text
 ---
 environment 'default' does not satisfy the requirements of the project for platform 'linux-64'
     Diagnostic severity: error
-    Caused by: the input hash for 'child-package' (f0d841a0cfd56becd0041a6bbcd215a19ce9c34c08530a98b642381af8ebd32a) does not match the hash in the lock-file (64a8e9eb88c4f6e944a37279a38a47fe7872454fb62bcafad63d200aef4b4a05)
+    Caused by: the input hash for 'child-package' (6a7fcb5c9f728504123fff40635207fb963b77f26b1a2dffb2993efa7f81559d) does not match the hash in the lock-file (64a8e9eb88c4f6e944a37279a38a47fe7872454fb62bcafad63d200aef4b4a05)

crates/pixi_glob/src/snapshots/pixi_glob__glob_hash__test__glob_hash_case_1_satisfiability.snap

@@ -1,10 +1,11 @@
 ---
 source: crates/pixi_glob/src/glob_hash.rs
 expression: snapshot
+snapshot_kind: text
 ---
 Globs:
 - tests/data/satisfiability/source-dependency/**/*
-Hash: 4ae275fa46ad1fa335806cd37767a8fe530046fb38aea40b24527fddf3a769b8
+Hash: 15638d2bfdb15971bb19d0593ee872437fb6a5c88b143e01f3044e473888e39c
 Matched files:
 - tests/data/satisfiability/source-dependency/child-package/pixi.toml
 - tests/data/satisfiability/source-dependency/pixi.lock