fix: enhance error handling for path supported manifests

crates/pixi_build_discovery/Cargo.toml

@@ -27,6 +27,7 @@ pixi_consts = { workspace = true }
 pixi_manifest = { workspace = true }
 pixi_spec = { workspace = true }
 pixi_spec_containers = { workspace = true }
+tracing = { workspace = true }
 
 [dev-dependencies]
 insta = { workspace = true, features = [

crates/pixi_build_discovery/src/discovery.rs

@@ -9,7 +9,9 @@ use ordermap::OrderMap;
 use pixi_build_type_conversions::{to_project_model_v1, to_target_selector_v1};
 use pixi_build_types::{ProjectModelV1, TargetSelectorV1};
 use pixi_config::Config;
-use pixi_consts::consts::{RATTLER_BUILD_DIRS, RATTLER_BUILD_FILE_NAMES, ROS_BACKEND_FILE_NAMES};
+use pixi_consts::consts::{
+    KNOWN_MANIFEST_FILES, RATTLER_BUILD_DIRS, RATTLER_BUILD_FILE_NAMES, ROS_BACKEND_FILE_NAMES,
+};
 use pixi_manifest::{
     DiscoveryStart, ExplicitManifestError, PackageManifest, PrioritizedChannel, WithProvenance,
     WorkspaceDiscoverer, WorkspaceDiscoveryError, WorkspaceManifest,
@@ -113,11 +115,9 @@ pub enum DiscoveryError {
     #[diagnostic(help("This is often caused by an internal error. Please report this issue."))]
     SpecConversionError(pixi_spec::SpecConversionError),
 
-    #[error("the source directory '{0}', does not contain a supported manifest")]
-    #[diagnostic(help(
-        "Ensure that the source directory contains a valid pixi.toml, pyproject.toml, recipe.yaml, package.xml or mojoproject.toml file."
-    ))]
-    FailedToDiscover(String),
+    #[error("the source directory '{path}', does not contain a supported manifest")]
+    #[diagnostic(help("{help}"))]
+    FailedToDiscover { path: String, help: String },
 
     #[error("the manifest path '{0}', does not have a parent directory")]
     NoParentDir(PathBuf),
@@ -159,7 +159,7 @@ impl DiscoveredBackend {
                 }
                 let source_dir = source_path
                     .parent()
-                    .expect("the recipe must live somewhere");
+                    .expect("the package.xml must live somewhere");
                 return Self::from_ros_package(
                     source_dir.to_path_buf(),
                     source_path,
@@ -182,9 +182,27 @@ impl DiscoveredBackend {
             return Ok(pixi);
         }
 
-        Err(DiscoveryError::FailedToDiscover(
-            source_path.to_string_lossy().to_string(),
-        ))
+        // Test whether we can discover as a ROS package.
+        let help_msg = if enabled_protocols.enable_pixi
+            && ROS_BACKEND_FILE_NAMES
+                .iter()
+                .any(|&f| source_path.join(f).is_file())
+        {
+            format!(
+                "ROS packages require you to specify the 'package.xml' file path directly, due to supporting more backends in the future. Or ensure that the source directory contains a valid manifest file: {}.",
+                KNOWN_MANIFEST_FILES.join(", ")
+            )
+        } else {
+            format!(
+                "Ensure that the source directory contains a valid manifest file: {}.",
+                KNOWN_MANIFEST_FILES.join(", ")
+            )
+        };
+
+        Err(DiscoveryError::FailedToDiscover {
+            path: source_path.to_string_lossy().to_string(),
+            help: help_msg,
+        })
     }
 
     /// Construct a new instance based on a specific `recipe.yaml` file in the
@@ -350,6 +368,11 @@ impl DiscoveredBackend {
                 )?));
             }
         }
+        tracing::trace!(
+            "No rattler-build manifests ({}) found in '{}'",
+            RATTLER_BUILD_FILE_NAMES.join(", "),
+            source_dir.display()
+        );
         Ok(None)
     }
 

crates/pixi_build_discovery/tests/discovery.rs

@@ -122,3 +122,39 @@ fn test_direct_package_xml() {
         assert_discover_snapshot ! ( & path);
     });
 }
+
+#[test]
+fn test_ros_discovery_priority() {
+    // Test that ROS packages are discovered after rattler-build recipes
+    // Create a test case with both package.xml and recipe.yaml
+    let path = dunce::canonicalize(discovery_directory().join("ros-priority")).unwrap();
+    let file_path = Path::new(file!()).parent().unwrap();
+    let channel_config = ChannelConfig::default_with_root_dir(file_path.to_owned());
+
+    match DiscoveredBackend::discover(&path, &channel_config, &EnabledProtocols::default()) {
+        Ok(backend) => {
+            // Should discover rattler-build backend, not ROS
+            insta::with_settings!({
+                filters => vec![
+                    (path.to_string_lossy().replace(r"\", r"\\").as_str(), "file://<ROOT>"),
+                    (r"\\", r"/"),
+                ],
+            }, {
+                assert_yaml_snapshot!(backend, {
+                    "[\"init-params\"][\"manifest-path\"]" => insta::dynamic_redaction(|value, _path| {
+                        redact_path(value.as_str().unwrap())
+                    }),
+                    "[\"init-params\"][\"workspace-root\"]" => insta::dynamic_redaction(|value, _path| {
+                        redact_path(value.as_str().unwrap())
+                    }),
+                    "[\"init-params\"][\"source-anchor\"]" => insta::dynamic_redaction(|value, _path| {
+                        redact_path(value.as_str().unwrap())
+                    }),
+                });
+            });
+        }
+        Err(err) => {
+            assert_snapshot!(pixi_test_utils::format_diagnostic(&err));
+        }
+    }
+}

crates/pixi_build_discovery/tests/snapshots/discovery__discovery@ros-package.snap

@@ -1,35 +1,8 @@
 ---
 source: crates/pixi_build_discovery/tests/discovery.rs
-expression: backend
+expression: "pixi_test_utils :: format_diagnostic(& err)"
 input_file: tests/data/discovery/ros-package/TEST-CASE
 ---
-backend-spec:
-  type: json-rpc
-  name: pixi-build-ros
-  command:
-    type: environment-spec
-    requirement:
-      - pixi-build-ros
-      - "*"
-    channels:
-      - "https://conda.anaconda.org/conda-forge"
-      - "https://prefix.dev/pixi-build-backends"
-init-params:
-  workspace-root: "file://<ROOT>/ros-package"
-  source: ~
-  source-anchor: "file://<ROOT>/ros-package"
-  manifest-path: "file://<ROOT>/ros-package/package.xml"
-  project-model:
-    name: ~
-    version: ~
-    description: ~
-    authors: ~
-    license: ~
-    licenseFile: ~
-    readme: ~
-    homepage: ~
-    repository: ~
-    documentation: ~
-    targets: ~
-  configuration: ~
-  target-configuration: ~
+  × the source directory '<CARGO_ROOT>/tests/data/discovery/ros-package', does not contain a supported manifest
+  help: ROS packages require you to specify the 'package.xml' file path directly, due to supporting more backends in the future. Or ensure that the source directory contains a valid manifest file:
+        pixi.toml, pyproject.toml, mojoproject.toml, recipe.yaml, recipe.yml.

crates/pixi_build_discovery/tests/snapshots/discovery__ros_discovery_priority.snap

@@ -0,0 +1,22 @@
+---
+source: crates/pixi_build_discovery/tests/discovery.rs
+expression: backend
+---
+backend-spec:
+  type: json-rpc
+  name: pixi-build-rattler-build
+  command:
+    type: environment-spec
+    requirement:
+      - pixi-build-rattler-build
+      - "*"
+    channels:
+      - "https://prefix.dev/conda-forge"
+init-params:
+  workspace-root: "file://<ROOT>/ros-priority"
+  build-source: ~
+  source-anchor: "file://<ROOT>/ros-priority"
+  manifest-path: "file://<ROOT>/ros-priority/recipe.yaml"
+  project-model: ~
+  configuration: ~
+  target-configuration: ~

crates/pixi_consts/src/consts.rs

@@ -112,10 +112,14 @@ pub const RATTLER_BUILD_FILE_NAMES: [&str; 2] = ["recipe.yaml", "recipe.yml"];
 pub const RATTLER_BUILD_DIRS: [&str; 2] = ["", "recipe"];
 pub const ROS_BACKEND_FILE_NAMES: [&str; 1] = ["package.xml"];
 
-/// Known manifest file names that indicate the path points to a file rather than a directory.
-pub const KNOWN_MANIFEST_FILES: &[&str] =
-    &[WORKSPACE_MANIFEST, PYPROJECT_MANIFEST, MOJOPROJECT_MANIFEST];
-
+pub static KNOWN_MANIFEST_FILES: LazyLock<Vec<&'static str>> = LazyLock::new(|| {
+    let mut v = Vec::new();
+    v.push(WORKSPACE_MANIFEST);
+    v.push(PYPROJECT_MANIFEST);
+    v.push(MOJOPROJECT_MANIFEST);
+    v.extend(RATTLER_BUILD_FILE_NAMES);
+    v
+});
 pub static TASK_STYLE: LazyLock<Style> = LazyLock::new(|| Style::new().blue());
 pub static TASK_ERROR_STYLE: LazyLock<Style> = LazyLock::new(|| Style::new().red());
 pub static PLATFORM_STYLE: LazyLock<Style> = LazyLock::new(|| Style::new().yellow());

crates/pixi_spec/src/source_anchor.rs

@@ -1,4 +1,4 @@
-use pixi_consts::consts::{KNOWN_MANIFEST_FILES, RATTLER_BUILD_FILE_NAMES, ROS_BACKEND_FILE_NAMES};
+use pixi_consts::consts::KNOWN_MANIFEST_FILES;
 use typed_path::{
     Utf8Component, Utf8Encoding, Utf8Path, Utf8PathBuf, Utf8TypedPath, Utf8TypedPathBuf,
 };
@@ -108,11 +108,7 @@ impl SourceAnchor {
 /// to the workspace root.
 fn is_known_manifest_file(path: Utf8TypedPath<'_>) -> bool {
     path.file_name()
-        .map(|name| {
-            KNOWN_MANIFEST_FILES.contains(&name)
-                || RATTLER_BUILD_FILE_NAMES.contains(&name)
-                || ROS_BACKEND_FILE_NAMES.contains(&name)
-        })
+        .map(|name| KNOWN_MANIFEST_FILES.contains(&name))
         .unwrap_or(false)
 }
 

tests/data/discovery/ros-package/TEST-CASE

@@ -0,0 +1 @@
+Marks this directory as a test-case for discovery tests.

tests/data/discovery/ros-priority/package.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0"?>
+<package format="3">
+  <name>priority_test_package</name>
+  <version>0.2.0</version>
+</package>

tests/data/discovery/ros-priority/recipe.yaml

@@ -0,0 +1,6 @@
+package:
+  name: priority-test
+  version: 0.1.0
+
+build:
+  script: echo "This should be discovered"

tests/data/discovery/ros-with-workspace/package.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0"?>
+<package format="3">
+  <name>workspace_test_package</name>
+  <version>1.0.0</version>
+</package>

tests/data/discovery/ros-with-workspace/pixi.toml

@@ -0,0 +1,4 @@
+[workspace]
+channels = ["robostack-staging", "conda-forge"]
+name = "ros-workspace"
+platforms = ["linux-64"]