Make manifest address parsing error more descriptive (diem#75)

Author: macalinao

language/move-core/types/src/account_address.rs

@@ -267,7 +267,11 @@ pub struct AccountAddressParseError;
 
 impl fmt::Display for AccountAddressParseError {
     fn fmt(&self, f: &mut fmt::Formatter) -> std::fmt::Result {
-        write!(f, "Unable to parse AccountAddress")
+        write!(
+            f,
+            "Unable to parse AccountAddress (must be hex string of length {})",
+            AccountAddress::LENGTH
+        )
     }
 }
 

language/tools/move-package/src/source_package/manifest_parser.rs

@@ -213,7 +213,10 @@ pub fn parse_addresses(tval: TV) -> Result<PM::AddressDeclarations> {
                         } else if addresses
                             .insert(
                                 ident,
-                                Some(parse_address_literal(entry_str).context("Invalid address")?),
+                                Some(parse_address_literal(entry_str).context(format!(
+                                    "Invalid address '{}' encountered.",
+                                    entry_str
+                                ))?),
                             )
                             .is_some()
                         {
@@ -251,7 +254,10 @@ pub fn parse_dev_addresses(tval: TV) -> Result<PM::DevAddressDeclarations> {
                         } else if addresses
                             .insert(
                                 ident,
-                                parse_address_literal(entry_str).context("Invalid address")?,
+                                parse_address_literal(entry_str).context(format!(
+                                    "Invalid address '{}' encountered.",
+                                    entry_str
+                                ))?,
                             )
                             .is_some()
                         {