In 24.11 I tried to import 5000 records with items attached, everything went well. Then I tried to import 9996 records, it fails. The detail of task displayed 0 / 9996, then something like 1390 / 9996, then 0 / 9996 with the status "Failed" I used the same records (duplicating the xml file and modifying barcodes to avoid issues), so the problem must be related to Koha.
Probably a general technical limitation of Koha? But I haven't found a specific ticket, and if an fix/improvement could be made to remove this limitation on the number of records, that would be great.
Does this work using the batch importer? Just asking as I regularly load 40k records that way and it might help to nail the source.
I will ask explaination to our vendor Biblibre. Maybe linked to https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=26128 (plack issue) ?
Another test went well, with 10000 items imported in 6 minutes. But I'm leaving the ticket open while I investigate further...