addition error definitions (#2107)

* remove low information density error doc comments

* another round of error dancing

* fix compilation

* remove stale `None` argument

* adjust test, minor slip in command

* only add AvailabilityError for full node features

* another None where none shuld be

polkadot/node/subsystem/src/lib.rs

@@ -77,7 +77,7 @@ impl PartialEq for ActiveLeavesUpdate {
 	///
 	/// Instead, it means equality when `activated` and `deactivated` are considered as sets.
 	fn eq(&self, other: &Self) -> bool {
-		self.activated.len() == other.activated.len() && self.deactivated.len() == other.deactivated.len() 
+		self.activated.len() == other.activated.len() && self.deactivated.len() == other.deactivated.len()
 			&& self.activated.iter().all(|a| other.activated.contains(a))
 			&& self.deactivated.iter().all(|a| other.deactivated.contains(a))
 	}
@@ -151,13 +151,13 @@ pub enum SubsystemError {
 		/// An additional anotation tag for the origin of `source`.
 		origin: &'static str,
 		/// The wrapped error. Marked as source for tracking the error chain.
-		#[source] source: Box<dyn std::error::Error + Send>
+		#[source] source: Box<dyn 'static + std::error::Error + Send + Sync>
 	},
 }
 
 impl SubsystemError {
 	/// Adds a `str` as `origin` to the given error `err`.
-	pub fn with_origin<E: 'static + Send + std::error::Error>(origin: &'static str, err: E) -> Self {
+	pub fn with_origin<E: 'static + Send + Sync + std::error::Error>(origin: &'static str, err: E) -> Self {
 		Self::FromOrigin { origin, source: Box::new(err) }
 	}
 }