PhpMaker has a debug setting under Toosl->Advanced Settings. Set that to true, generate and you can see a lot of debugging output. The problem is, when you are through you have to unset the flag and generate again. Here's a quicker way:
Open ewcfg?.php where ? represents your PhpMaker version. In my case, ewcfg8.php.
Look for the line that says: define("EW_DEBUG_ENABLED", FALSE, TRUE);
It's on line 8 in ewcfg8.php. Set the FALSE flag to TRUE. Save and upload the file.
It should now say: define("EW_DEBUG_ENABLED", TRUE, TRUE);
When you are through debugging, set it back to FALSE, save and upload.
It should now say: define("EW_DEBUG_ENABLED", FALSE, TRUE);
That's all there is to it. Same results and much faster.