Merge 143732d2a82c057f9efe48895fc798e422894fec into af2253ba16dfdc731e787e3a43a6f6a63ea65e0a

- restore ability to override a package locally
- cut down on some repeated logic
- more detailed errors

crates/typst-cli/src/world.rs

@@ -404,7 +404,9 @@ fn system_path(
 
     // Join the path to the root. If it tries to escape, deny
     // access. Note: It can still escape via symlinks.
-    id.vpath().resolve(root).ok_or(FileError::AccessDenied)
+    id.vpath()
+        .resolve(root)
+        .ok_or_else(|| FileError::AccessDenied(id.vpath().as_rootless_path().into()))
 }
 
 /// Reads a file from a `FileId`.
@@ -427,7 +429,7 @@ fn read(
 fn read_from_disk(path: &Path) -> FileResult<Vec<u8>> {
     let f = |e| FileError::from_io(e, path);
     if fs::metadata(path).map_err(f)?.is_dir() {
-        Err(FileError::IsDirectory)
+        Err(FileError::IsDirectory(path.into()))
     } else {
         fs::read(path).map_err(f)
     }

crates/typst-kit/src/package.rs

@@ -87,6 +87,7 @@ impl PackageStorage {
     ) -> PackageResult<PathBuf> {
         let subdir = format!("{}/{}/{}", spec.namespace, spec.name, spec.version);
 
+        // By default, search for the package locally
         if let Some(packages_dir) = &self.package_path {
             let dir = packages_dir.join(&subdir);
             if dir.exists() {
@@ -94,6 +95,7 @@ impl PackageStorage {
             }
         }
 
+        // As a fallback, look into the cache and possibly download from network.
         if let Some(cache_dir) = &self.package_cache_path {
             let dir = cache_dir.join(&subdir);
             if dir.exists() {
@@ -102,14 +104,42 @@ impl PackageStorage {
 
             // Download from network if it doesn't exist yet.
             if spec.namespace == DEFAULT_NAMESPACE {
-                self.download_package(spec, cache_dir, progress)?;
-                if dir.exists() {
-                    return Ok(dir);
-                }
+                return self.download_package(spec, cache_dir, progress);
             }
         }
 
-        Err(PackageError::NotFound(spec.clone()))
+        // None of the strategies above found the package, so all code paths
+        // from now on fail. The rest of the function is only to determine the
+        // cause of the failure.
+        // We try `namespace/` then `namespace/name/` then `namespace/name/version/`
+        // and see where the first error occurs.
+        let not_found = |msg| Err(PackageError::NotFound(spec.clone(), msg));
+
+        let Some(packages_dir) = &self.package_path else {
+            return not_found(eco_format!("cannot access local package storage"));
+        };
+        let namespace_dir = packages_dir.join(format!("{}", spec.namespace));
+        if !namespace_dir.exists() {
+            return not_found(eco_format!(
+                "namespace @{} should be located at {}",
+                spec.namespace,
+                namespace_dir.display()
+            ));
+        }
+        let package_dir = namespace_dir.join(format!("{}", spec.name));
+        if !package_dir.exists() {
+            return not_found(eco_format!(
+                "{} does not have package '{}'",
+                namespace_dir.display(),
+                spec.name
+            ));
+        }
+        let latest = self.determine_latest_version(&spec.versionless()).ok();
+        Err(PackageError::VersionNotFound(
+            spec.clone(),
+            latest,
+            eco_format!("{}", namespace_dir.display()),
+        ))
     }
 
     /// Tries to determine the latest version of a package.
@@ -171,21 +201,29 @@ impl PackageStorage {
         spec: &PackageSpec,
         cache_dir: &Path,
         progress: &mut dyn Progress,
-    ) -> PackageResult<()> {
+    ) -> PackageResult<PathBuf> {
         assert_eq!(spec.namespace, DEFAULT_NAMESPACE);
 
-        let url = format!(
-            "{DEFAULT_REGISTRY}/{DEFAULT_NAMESPACE}/{}-{}.tar.gz",
-            spec.name, spec.version
-        );
+        let namespace_url = format!("{DEFAULT_REGISTRY}/{DEFAULT_NAMESPACE}");
+        let url = format!("{namespace_url}/{}-{}.tar.gz", spec.name, spec.version);
 
         let data = match self.downloader.download_with_progress(&url, progress) {
             Ok(data) => data,
             Err(ureq::Error::Status(404, _)) => {
                 if let Ok(version) = self.determine_latest_version(&spec.versionless()) {
-                    return Err(PackageError::VersionNotFound(spec.clone(), version));
+                    return Err(PackageError::VersionNotFound(
+                        spec.clone(),
+                        Some(version),
+                        eco_format!("{namespace_url}"),
+                    ));
                 } else {
-                    return Err(PackageError::NotFound(spec.clone()));
+                    return Err(PackageError::NotFound(
+                        spec.clone(),
+                        eco_format!(
+                            "{namespace_url} does not have package '{}'",
+                            spec.name
+                        ),
+                    ));
                 }
             }
             Err(err) => {
@@ -235,8 +273,8 @@ impl PackageStorage {
         // broken packages still occur even with the rename safeguard, we might
         // consider more complex solutions like file locking or checksums.
         match fs::rename(&tempdir, &package_dir) {
-            Ok(()) => Ok(()),
-            Err(err) if err.kind() == io::ErrorKind::DirectoryNotEmpty => Ok(()),
+            Ok(()) => Ok(package_dir),
+            Err(err) if err.kind() == io::ErrorKind::DirectoryNotEmpty => Ok(package_dir),
             Err(err) => Err(error("failed to move downloaded package directory", err)),
         }
     }

crates/typst-library/src/diag.rs

@@ -439,13 +439,13 @@ pub enum FileError {
     /// A file was not found at this path.
     NotFound(PathBuf),
     /// A file could not be accessed.
-    AccessDenied,
+    AccessDenied(PathBuf),
     /// A directory was found, but a file was expected.
-    IsDirectory,
+    IsDirectory(PathBuf),
     /// The file is not a Typst source file, but should have been.
-    NotSource,
+    NotSource(PathBuf),
     /// The file was not valid UTF-8, but should have been.
-    InvalidUtf8,
+    InvalidUtf8(Option<PathBuf>),
     /// The package the file is part of could not be loaded.
     Package(PackageError),
     /// Another error.
@@ -459,11 +459,11 @@ impl FileError {
     pub fn from_io(err: io::Error, path: &Path) -> Self {
         match err.kind() {
             io::ErrorKind::NotFound => Self::NotFound(path.into()),
-            io::ErrorKind::PermissionDenied => Self::AccessDenied,
+            io::ErrorKind::PermissionDenied => Self::AccessDenied(path.into()),
             io::ErrorKind::InvalidData
                 if err.to_string().contains("stream did not contain valid UTF-8") =>
             {
-                Self::InvalidUtf8
+                Self::InvalidUtf8(Some(path.into()))
             }
             _ => Self::Other(Some(eco_format!("{err}"))),
         }
@@ -478,10 +478,19 @@ impl Display for FileError {
             Self::NotFound(path) => {
                 write!(f, "file not found (searched at {})", path.display())
             }
-            Self::AccessDenied => f.pad("failed to load file (access denied)"),
-            Self::IsDirectory => f.pad("failed to load file (is a directory)"),
-            Self::NotSource => f.pad("not a typst source file"),
-            Self::InvalidUtf8 => f.pad("file is not valid utf-8"),
+            Self::AccessDenied(path) => {
+                write!(f, "failed to load file {} (access denied)", path.display())
+            }
+            Self::IsDirectory(path) => {
+                write!(f, "failed to load file {} (is a directory)", path.display())
+            }
+            Self::NotSource(path) => {
+                write!(f, "{} is not a typst source file", path.display())
+            }
+            Self::InvalidUtf8(Some(path)) => {
+                write!(f, "file {} is not valid utf-8", path.display())
+            }
+            Self::InvalidUtf8(None) => f.pad("file is not valid utf-8"),
             Self::Package(error) => error.fmt(f),
             Self::Other(Some(err)) => write!(f, "failed to load file ({err})"),
             Self::Other(None) => f.pad("failed to load file"),
@@ -491,13 +500,13 @@ impl Display for FileError {
 
 impl From<Utf8Error> for FileError {
     fn from(_: Utf8Error) -> Self {
-        Self::InvalidUtf8
+        Self::InvalidUtf8(None)
     }
 }
 
 impl From<FromUtf8Error> for FileError {
     fn from(_: FromUtf8Error) -> Self {
-        Self::InvalidUtf8
+        Self::InvalidUtf8(None)
     }
 }
 
@@ -518,13 +527,15 @@ pub type PackageResult<T> = Result<T, PackageError>;
 
 /// An error that occurred while trying to load a package.
 ///
-/// Some variants have an optional string can give more details, if available.
+/// Some variants have an optional string that can give more details, if available.
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
 pub enum PackageError {
     /// The specified package does not exist.
-    NotFound(PackageSpec),
+    /// Additionally provides information on where we tried to find the package.
+    NotFound(PackageSpec, EcoString),
     /// The specified package found, but the version does not exist.
-    VersionNotFound(PackageSpec, PackageVersion),
+    /// TODO: make the registry part of the error better typed
+    VersionNotFound(PackageSpec, Option<PackageVersion>, EcoString),
     /// Failed to retrieve the package through the network.
     NetworkFailed(Option<EcoString>),
     /// The package archive was malformed.
@@ -538,15 +549,20 @@ impl std::error::Error for PackageError {}
 impl Display for PackageError {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         match self {
-            Self::NotFound(spec) => {
-                write!(f, "package not found (searched for {spec})",)
+            Self::NotFound(spec, detail) => {
+                write!(f, "package not found: {detail} (searching for {spec})",)
             }
-            Self::VersionNotFound(spec, latest) => {
+            Self::VersionNotFound(spec, latest, registry) => {
                 write!(
                     f,
-                    "package found, but version {} does not exist (latest is {})",
-                    spec.version, latest,
-                )
+                    "package '{}' found, but version {} does not exist",
+                    spec.name, spec.version
+                )?;
+                if let Some(version) = latest {
+                    write!(f, " (latest version provided by {registry} is {version})")
+                } else {
+                    write!(f, " ({registry} contains no versions for this package)")
+                }
             }
             Self::NetworkFailed(Some(err)) => {
                 write!(f, "failed to download package ({err})")

crates/typst/src/lib.rs

@@ -191,7 +191,7 @@ fn hint_invalid_main_file(
     file_error: FileError,
     input: FileId,
 ) -> EcoVec<SourceDiagnostic> {
-    let is_utf8_error = matches!(file_error, FileError::InvalidUtf8);
+    let is_utf8_error = matches!(file_error, FileError::InvalidUtf8(_));
     let mut diagnostic =
         SourceDiagnostic::error(Span::detached(), EcoString::from(file_error));
 

tests/src/world.rs

@@ -172,7 +172,9 @@ pub(crate) fn system_path(id: FileId) -> FileResult<PathBuf> {
         None => PathBuf::new(),
     };
 
-    id.vpath().resolve(&root).ok_or(FileError::AccessDenied)
+    id.vpath()
+        .resolve(&root)
+        .ok_or_else(|| FileError::AccessDenied(id.vpath().as_rootless_path().into()))
 }
 
 /// Read a file.
@@ -186,7 +188,7 @@ pub(crate) fn read(path: &Path) -> FileResult<Cow<'static, [u8]>> {
 
     let f = |e| FileError::from_io(e, path);
     if fs::metadata(path).map_err(f)?.is_dir() {
-        Err(FileError::IsDirectory)
+        Err(FileError::IsDirectory(path.into()))
     } else {
         fs::read(path).map(Cow::Owned).map_err(f)
     }

tests/suite/scripting/import.typ

@@ -302,11 +302,11 @@
 #import 5 as x
 
 --- import-from-string-invalid ---
-// Error: 9-11 failed to load file (is a directory)
+// Error: 9-11 failed to load file tests/suite/scripting (is a directory)
 #import "": name
 
 --- import-from-string-renamed-invalid ---
-// Error: 9-11 failed to load file (is a directory)
+// Error: 9-11 failed to load file tests/suite/scripting (is a directory)
 #import "" as x
 
 --- import-file-not-found-invalid ---
@@ -483,3 +483,4 @@ This is never reached.
 --- import-from-file-package-lookalike ---
 // Error: 9-28 file not found (searched at tests/suite/scripting/#test/mypkg:1.0.0)
 #import "#test/mypkg:1.0.0": *
+