error_handler.rb in nanoc-4.9.7

- old
+ new

@@ -244,11 +244,11 @@
           else
             "Install the '#{gem_name}' gem using `gem install #{gem_name}`."
           end
         end
       when RuntimeError
-        if error.message =~ /^can't modify frozen/
+        if /^can't modify frozen/.match?(error.message)
           'You attempted to modify immutable data. Some data cannot ' \
           'be modified once compilation has started. Such data includes ' \
           'content and attributes of items and layouts, and filter arguments.'
         end
       when Errno::EADDRINUSE
@@ -284,16 +284,25 @@
     def write_error_message(stream, error, verbose: false)
       write_section_header(stream, 'Message', verbose: verbose)
 
       error = unwrap_error(error)
 
-      message = "#{error.class}: #{error.message}"
+      message = "#{error.class}: #{message_for_error(error)}"
       unless verbose
         message = "\e[1m\e[31m" + message + "\e[0m"
       end
       stream.puts message
       resolution = resolution_for(error)
       stream.puts resolution.to_s if resolution
+    end
+
+    def message_for_error(error)
+      case error
+      when JsonSchema::AggregateError
+        "\n" + error.errors.map { |e| "  * #{e.pointer}: #{e.message}" }.join("\n")
+      else
+        error.message
+      end
     end
 
     def write_item_rep(stream, error, verbose: false)
       return unless error.is_a?(Nanoc::Int::Errors::CompilationError)
 