feat: add more context to EnvelopeErrors

Some transparent errors did not have any context on inner
error either and just forward

Author: ss2165

hugr-cli/tests/validate.rs

@@ -126,6 +126,7 @@ fn test_mermaid_invalid(bad_hugr_string: String, mut cmd: Command) {
     cmd.write_stdin(bad_hugr_string);
     cmd.assert()
         .failure()
+        .stderr(contains("unconnected port"))
         .stderr(contains("Error validating HUGR"));
 }
 
@@ -137,6 +138,7 @@ fn test_bad_hugr(bad_hugr_string: String, mut val_cmd: Command) {
     val_cmd
         .assert()
         .failure()
+        .stderr(contains("unconnected port"))
         .stderr(contains("Error validating HUGR"));
 }
 
@@ -149,7 +151,8 @@ fn test_bad_json(mut val_cmd: Command) {
     val_cmd
         .assert()
         .failure()
-        .stderr(contains("Error decoding HUGR envelope"));
+        .stderr(contains("Error decoding HUGR envelope"))
+        .stderr(contains("missing field"));
 }
 
 #[rstest]
@@ -234,5 +237,6 @@ fn test_validate_known_generator(invalid_hugr_with_generator: Vec<u8>, mut val_c
         .assert()
         .failure()
         .stderr(contains("Error validating HUGR"))
+        .stderr(contains("unconnected port"))
         .stderr(contains("generated by test-generator-v1.0.1"));
 }

hugr-core/src/envelope.rs

@@ -304,7 +304,7 @@ pub enum EnvelopeError {
         source: hugr_model::v0::binary::WriteError,
     },
     /// Error reading a HUGR model payload.
-    #[error(transparent)]
+    #[error("Model text parsing error")]
     ModelTextRead {
         /// The source error.
         #[from]

hugr-core/src/envelope/package_json.rs

@@ -77,15 +77,16 @@ pub(super) fn to_json_writer<'h>(
 /// Error raised while loading a package.
 #[derive(Debug, Display, Error, From)]
 #[non_exhaustive]
+#[display("Error reading or writing a package in JSON format.")]
 pub enum PackageEncodingError {
     /// Error raised while parsing the package json.
-    JsonEncoding(serde_json::Error),
+    JsonEncoding(#[from] serde_json::Error),
     /// Error raised while reading from a file.
-    IOError(io::Error),
+    IOError(#[from] io::Error),
     /// Could not resolve the extension needed to encode the hugr.
-    ExtensionResolution(WithGenerator<ExtensionResolutionError>),
+    ExtensionResolution(#[from] WithGenerator<ExtensionResolutionError>),
     /// Error raised while checking for breaking extension version mismatch.
-    ExtensionVersion(WithGenerator<ExtensionBreakingError>),
+    ExtensionVersion(#[from] WithGenerator<ExtensionBreakingError>),
 }
 
 /// A private package structure implementing the serde traits.

hugr-core/src/extension.rs

@@ -706,6 +706,7 @@ pub enum ExtensionRegistryError {
 /// An error that can occur while loading an extension registry.
 #[derive(Debug, Error)]
 #[non_exhaustive]
+#[error("Extension registry load error")]
 pub enum ExtensionRegistryLoadError {
     /// Deserialization error.
     #[error(transparent)]

hugr-model/src/v0/ast/resolve.rs

@@ -365,6 +365,7 @@ impl<'a> Context<'a> {
 /// Error that may occur in [`Module::resolve`].
 #[derive(Debug, Clone, Error)]
 #[non_exhaustive]
+#[error("Error resolving model module")]
 pub enum ResolveError {
     /// Unknown variable.
     #[error("unknown var: {0}")]

hugr-model/src/v0/binary/read.rs

@@ -8,6 +8,7 @@ use std::io::BufRead;
 /// An error encountered while deserialising a model.
 #[derive(Debug, derive_more::From, derive_more::Display, derive_more::Error)]
 #[non_exhaustive]
+#[display("Error reading a HUGR model payload.")]
 pub enum ReadError {
     #[from(forward)]
     /// An error encountered while decoding a model from a `capnproto` buffer.

hugr-model/src/v0/binary/write.rs

@@ -7,7 +7,9 @@ use crate::v0::table;
 /// An error encounter while serializing a model.
 #[derive(Debug, derive_more::From, derive_more::Display, derive_more::Error)]
 #[non_exhaustive]
+#[display("Error encoding a package in HUGR model format.")]
 pub enum WriteError {
+    #[from(forward)]
     /// An error encountered while encoding a `capnproto` buffer.
     EncodingError(capnp::Error),
 }