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jordi · 05-02-2026, 08:41 AM

I've investigated the issue a little bit further:

After starting calibre with the "DYLD_PRINT_LIBRARIES=1" parameter I figured out, that calibre stops for a quite amount of time when the System Library extension IOUSBLib is loaded.

I'm running MacOS with no external readers connected. So I've tried to disable all Calibre mtp plugins, but that doesn't changed anything.

So instead I've removed the libusb.so plugin from calibre and now it works...

Does calibre scan for an external device on startup and is there a timeout for about 70 sec. that has to be passed, before the startup process continues?

And is there another way to avoid this devices scan?

05-02-2026, 08:41 AM	#5
jordi Junior Member Posts: 9 Karma: 10 Join Date: Apr 2026 Device: iPad	I've investigated the issue a little bit further: After starting calibre with the "DYLD_PRINT_LIBRARIES=1" parameter I figured out, that calibre stops for a quite amount of time when the System Library extension IOUSBLib is loaded. I'm running MacOS with no external readers connected. So I've tried to disable all Calibre mtp plugins, but that doesn't changed anything. So instead I've removed the libusb.so plugin from calibre and now it works... Does calibre scan for an external device on startup and is there a timeout for about 70 sec. that has to be passed, before the startup process continues? And is there another way to avoid this devices scan?