trying to debug, print not printing!

[hobleyd]

Hello,

I am playing around with syncing to calibre; I have an issue whereby updates on my device are not being picked up by calibre. Obviously I have stuffed something up.

So, I am trying to trace through the code. The current function of interest is set_books_in_library in src/calibre/gui2/device.py

Down in there, I have added some print statements:

        with BusyCursor():
            current_book_count = 0
            for booklist in booklists:
                print ('booklist: ', booklist)
                for book in booklist:
                    print ('processing book: ', book.uuid)

but while the print of booklist shows:

booklist:  [<calibre.devices.smart_device_app.driver.SDBook object at 0x7ff152f45ac0>, 
<calibre.devices.smart_device_app.driver.SDBook object at 0x7ff151ce78b0>, 
<calibre.devices.smart_device_app.driver.SDBook object at 0x7ff151ce79a0>,
<calibre.devices.smart_device_app.driver.SDBook object at 0x7ff151ce7850>, 
<calibre.devices.smart_device_app.driver.SDBook object at 0x7ff1500762e0>, 
<calibre.devices.smart_device_app.driver.SDBook object at 0x7ff150076070>, 
<calibre.devices.smart_device_app.driver.SDBook object at 0x7ff151ce76d0>]

the processing book line only outputs a single book and then appears to just stop outputting anything.

processing book: 8ed92285-8d1c-45c3-b756-f5f39fca4b52
DeviceJob: 2 Get list of books on device callback returned

Can anyone point me in the right direction as to why the output stops; calibre keeps running; everything looks normal except for the fact that the updates I pushed through are ignored and it is difficult to work out why without debug statements!

Cheers,
David

[kovidgoyal]

print will print, assuming you are running as calibre-debug -g, the problem is most likely the loop being aborted somewhere lower down.

[hobleyd]

Yes, I am running as calibre-debug -g; but how do I tell where it is bombing out?

I have added more debug statements:

                    current_book_count += 1
                    book.in_library = None
                    print('checking for uuid ', book.uuid, getattr(book, 'uuid', None))
                    if book.uuid in self.db_book_uuid_cache:
                        print('getattr(book, uuid, None) succeeded: ', uuid)
                        id_ = db_book_uuid_cache[book.uuid]
                        if updateq(id_, book):
                            update_book(id_, book)
                        book.in_library = 'UUID'
                        # ensure that the correct application_id is set
                        book.application_id = id_
                        continue
                    print('getattr(book, uuid, None) failed: ', uuid)

booklist:  [<calibre.devices.smart_device_app.driver.SDBook object at 0x7f88b07d9070>, <calibre.devices.smart_device_app.driver.SDBook object at 0x7f88b07ca4f0>, <calibre.devices.smart_device_app.driver.SDBook object at 0x7f88b07cad00>, <calibre.devices.smart_device_app.driver.SDBook object at 0x7f88c3d6e340>, <calibre.devices.smart_device_app.driver.SDBook object at 0x7f88c3d6e520>, <calibre.devices.smart_device_app.driver.SDBook object at 0x7f88c3d6e430>, <calibre.devices.smart_device_app.driver.SDBook object at 0x7f88c3d5edc0>] 

processing book:  The Color of Magic 8ed92285-8d1c-45c3-b756-f5f39fca4b52 

checking for uuid  8ed92285-8d1c-45c3-b756-f5f39fca4b52 8ed92285-8d1c-45c3-b756-f5f39fca4b52

while I see my initial print statement, I should get a succeeded or failed from the subsequent 2 print statements, but see nothing.

[jhowell]

Looking at that my best guess would be that an exception is occurring that is being caught elsewhere. Candidates for the cause of that might be self.db_book_uuid_cache or uuid (as opposed to book.uuid) being undefined.

[kovidgoyal]

Wrap the whole function contents in a try: except: and add a print to print out the exception in the except: block