print exception for tests (if occur or -v)

bin/example.rb

@@ -41,6 +41,11 @@ class Capture
 		STDERR.printf "[% 4d] \e[1;31mer\e[0m %s tests %s\e[J\n", @counter, $0.shellescape, command.shelljoin
 	end
 
+	def logexception prefix, exception
+		loginfo "#{prefix} (#{exception.class.name}) #{exception}"
+		exception.backtrace[0...-Kernel.caller.length].each {|l| loginfo "  #{l}" }
+	end
+
 	def loginfo text
 		STDERR.printf "           %s\n", text
 	end
@@ -64,7 +69,7 @@ class Capture
 		end
 	rescue Object
 		logfail command
-		loginfo "unexpected raise: (#{$!.class.name}) #$!"
+		logexception "unexpected raise:", $!
 		STDERR.puts
 	end
 
@@ -76,16 +81,16 @@ class Capture
 		if message === $!.message
 			logok command
 			if @verbose
-				loginfo "raised: (#{$!.class.name}) #$!"
+				logexception "raised:", $!
 				STDERR.puts
 			end
 		else
-			loginfo "unexpected message: (#{$!.class.name}) #$!"
+			logexception "unexpected message:", $!
 			STDERR.puts
 		end
 	rescue Object
 		logfail command
-		loginfo "unexpected raised: (#{$!.class.name}) #$!"
+		logexception "unexpected raised:", $!
 		STDERR.puts
 	end
 end