[bigwoof]

okay. this is very mysterious. I did some additional testing today.

all tests done with calibre in debug mode, and all sleep timers turned off on kobo libra h20. kobo has 3411 books. kobo and calibre server (running on a linux machine) are on the same local network connected via WiFi and a ethernet switch. Kobo UnCaged is set to Prefer Kepub and only kepub is selected as an acceptable format. so all the epubs need to be converted first.

run 1: debug enabled in kobo uncaged. turned it on. got to the "waiting" screen. waited quite a bit and then the kobo rebooted!! no connection made to calibre (running in debug mode)

run 2: debug enabled in uncaged. turned it on. got to the waiting screen and then it exited with a "all done" (forgot the actual wording) message. no connection made to calibre

run 3: turned off debug in uncaged and turned it on. got to waiting screen and then it actually connected (got to the next screen with the disconnect option). calibre shows all the books (a lot of them) being checked and the job spy said "reading book list". connection looks good from what the log says

SMART_DEV ( 454.01:450.304) run attempt to open device socket
SMART_DEV ( 455.77: 1.759) open
SMART_DEV ( 455.79: 0.000) _call_client GET_INITIALIZATION_INFO wfr True
SMART_DEV ( 455.84: 0.044) open Device can stream books True
SMART_DEV ( 455.85: 0.000) open Device can stream metadata True
SMART_DEV ( 455.86: 0.000) open Device can receive book binary True
SMART_DEV ( 455.87: 0.000) open Device can delete multiple books True
SMART_DEV ( 455.88: 0.000) open Device can use cached metadata True
SMART_DEV ( 455.89: 0.000) open Cache uses lpaths True
SMART_DEV ( 455.90: 0.000) open Can send OK to sendbook True
SMART_DEV ( 455.91: 0.000) open Can accept library info True
SMART_DEV ( 455.92: 0.000) open Will ask for update books False
SMART_DEV ( 455.94: 0.000) open Will set temp mark when syncing read False
SMART_DEV ( 455.95: 0.000) open Client device kind
SMART_DEV ( 455.96: 0.000) open Client device name Kobo Libra H2O
SMART_DEV ( 455.97: 0.000) open Client app name Kobo UNCaGED
SMART_DEV ( 455.98: 0.000) open App version #: 391
SMART_DEV ( 455.99: 0.000) open max_book_packet_len 4096
SMART_DEV ( 456.00: 0.000) open Device wants UUID file names False
SMART_DEV ( 456.04: 0.030) open selected formats ['kepub']
SMART_DEV ( 456.05: 0.000) open extension path lengths {'kepub': 38}
SMART_DEV ( 456.06: 0.000) open cover height 1680
SMART_DEV ( 456.07: 0.000) open Device is_read sync col None
SMART_DEV ( 456.08: 0.000) open Device is_read_date sync col None
SMART_DEV ( 456.09: 0.000) card_prefix

- After a few minutes of reading the books, it decides to convert and send 77 books

READING LIST: Sync Now - force_sync= False
READING LIST: Device found to sync to: Kobo Libra H2O efb49d4c-7d70-4e5e-912b-b81773b6d14d
READING LIST: Syncing 77 books in 'Send to Kobo' to: efb49d4c-7d70-4e5e-912b-b81773b6d14d (location:None)

- It starts jobs for converting all the books and sending them 1 by 1 to the Kobo once converted.

- it sends about 3 books but then on the 4th book, *Calibre* crashes. just dies dead. and there is nothing I can see in the logs to say why. UnCaged just pops up a message saying "All done".

These are the last 10 lines in the calibre debug log. as far as I can tell, they look fine and look the same as previous files that were sent successfully

No details available.
SMART_DEV (1246.27: 0.038) set_progress_reporter
Job: 90 Upload one book to the device: The Multiverse Project: Warhammer 40,000 started
SMART_DEV (1246.47: 0.000) set_plugboards
Device using plugboard kepub SMART_DEVICE_APP None
Setting metadata in: The Multiverse Project: Warhammer 40,000 at: /tmp/calibre_5.8.1_tmp_4fij358g/iz7_mxaycaltmpfmt.kepub
2021-01-01 11:08:35 [DEBUG] KEPUBMetadataWriter::set_metadata - self.__class__=<class 'calibre_plugins.kepubmdwriter.metadata.writer.KEP UBMetadataWriter'>
2021-01-01 11:08:35 [DEBUG] KEPUBMetadataWriter::set_metadata - covers=[<Element {http://www.idpf.org/2007/opf}meta at 0x7f8c47e8acc0>]
2021-01-01 11:08:35 [DEBUG] KEPUBMetadataWriter::set_metadata - cover_id=cover
2021-01-01 11:08:35 [DEBUG] KEPUBMetadataWriter::set_metadata - found cover

I checked the ku.log on the Kobo as well. nothing in there except the expected "Resizing covers" messages.

Not sure how to continue debugging this to be honest..

Ideas?