Calibre fails communication with PRS-500

[Xenophon]

I just tried to talk to my old-firmware PRS-500 using Calibre 0.6.40 on Mac OS X 10.6.2. I got the following error:

ERROR: ERROR: Unhandled exception: <b>Error</b>:Device sent zero bytes

Traceback (most recent call last):
  File "site-packages/calibre/gui2/__init__.py", line 249, in dispatch
  File "site-packages/calibre/gui2/ui.py", line 856, in device_detected
  File "site-packages/calibre/devices/prs500/driver.py", line 174, in run_session
  File "site-packages/calibre/devices/prs500/driver.py", line 621, in card_prefix
  File "site-packages/calibre/devices/prs500/driver.py", line 174, in run_session
  File "site-packages/calibre/devices/prs500/driver.py", line 453, in path_properties
  File "site-packages/calibre/devices/prs500/driver.py", line 424, in _bulk_read
  File "site-packages/calibre/devices/prs500/driver.py", line 411, in bulk_read_packet
  File "site-packages/calibre/devices/libusb.py", line 255, in bulk_read
Error: Device sent zero bytes

I haven't used the PRS-500 for quite a while, so I have no idea whether this has been happening for more than the most recent version of Calibre.

Xenophon

Opened ticket #4902 for this!

[Xenophon]

And... Kovid says that the last version of Calibre that supports old-firmware PRS-500 units is 0.6.29. Get it from SourceForge.

Xenophon

[kovidgoyal]

Yeah, from 0.6.30 onwards the OS X build system changed and the new build seems to cause some sort of multi threading issue with USB communications, which I just dont have the motivation to debug.