refactor(canopy): use miette::Report's Debug impl instead of a custom chain walker

Debug on miette::Report already renders the full error chain (with
Caused by: lines and source snippets). The custom chain() helper +
direct miette dep were both unnecessary — {err:?} in the wrapper's
map_err does the same job.

Drops the miette direct dep too (still transitive via bestool-canopy).

Author: passcod

Cargo.lock

@@ -18,7 +18,6 @@ jiff = { version = "0.2.25", features = ["serde"] }
 k8s-openapi = { version = "0.27.1", features = ["latest", "schemars"] }
 kube = { version = "3.1.0", default-features = false, features = ["runtime", "derive", "client", "rustls-tls", "ws"] }
 kube_quantity = "0.9.0"
-miette = "7.6.0"
 mimalloc = { version = "0.1", default-features = false }
 prometheus = "0.14.0"
 rand = "0.10.1"

Cargo.toml

@@ -103,7 +103,7 @@ impl Client {
 		self.inner
 			.restore_capabilities(&self.base_url, intents)
 			.await
-			.map_err(|err| Error::Canopy(format!("restore_capabilities: {}", chain(&err))))
+			.map_err(|err| Error::Canopy(format!("restore_capabilities: {err:?}")))
 	}
 
 	/// Fetch the consumer's desired-state worklist. Each entry is one
@@ -112,7 +112,7 @@ impl Client {
 		self.inner
 			.restore_worklist(&self.base_url)
 			.await
-			.map_err(|err| Error::Canopy(format!("restore_worklist: {}", chain(&err))))
+			.map_err(|err| Error::Canopy(format!("restore_worklist: {err:?}")))
 	}
 
 	/// Fetch short-lived read-only STS creds plus the repo password for a
@@ -127,8 +127,7 @@ impl Client {
 			.await
 			.map_err(|err| {
 				Error::Canopy(format!(
-					"restore_credentials({backup_type}, {group}): {}",
-					chain(&err)
+					"restore_credentials({backup_type}, {group}): {err:?}"
 				))
 			})
 	}
@@ -138,7 +137,7 @@ impl Client {
 		self.inner
 			.restore_verification(&self.base_url, report)
 			.await
-			.map_err(|err| Error::Canopy(format!("restore_verification: {}", chain(&err))))
+			.map_err(|err| Error::Canopy(format!("restore_verification: {err:?}")))
 	}
 
 	/// Direct access to the public-mTLS base URL the client is configured
@@ -149,19 +148,6 @@ impl Client {
 	}
 }
 
-/// Flatten a `miette::Report` (bestool-canopy's error type) to a single
-/// `outer: inner: root` line by walking its source chain. bestool wraps
-/// its errors with `.wrap_err(...)` which layers context around the
-/// underlying reqwest / io error, and plain `Display` on the report
-/// only shows the outermost message — losing the actually diagnostic
-/// bit.
-fn chain(err: &miette::Report) -> String {
-	err.chain()
-		.map(|e| e.to_string())
-		.collect::<Vec<_>>()
-		.join(": ")
-}
-
 /// Re-export the wire types pgro consumes verbatim from `bestool-canopy`.
 pub use bestool_canopy::{
 	BackupCredentials as Credentials, Outcome, RestoreCredentials as CredsResponse,