In the past, if you had a "coded_location_qualifier" that was too long, the whole MARC import would bust (see bug 30739). That's no longer the case anymore. However, if the item has a "coded_location_qualifier" like "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789", it will now just be ignored without any more information shown on the Web UI or in the worker logs. You wouldn't be able to troubleshoot this issue without writing your own code changes to Koha...
Bumped into this issue again today when I was trying to import a record that contained an item with a barcode that already existed in Koha.
I see in C4::ImportBatch::_batchCommitItems that duplicate barcode is the only error that will increment the items errored count...
Interestingly if the barcode is too long then the whole import fails and I see the following in worker-output.log, so that's something...: DBIx::Class::Storage::DBI::_dbh_execute(): DBI Exception: DBD::mysql::st execute failed: Data too long for column 'barcode' at row 1 at /kohadevbox/koha/Koha/Object.pm line 170
Looks like the coded location qualifier will cause the whole import to fail as well now, so that's good. You can see this in the worker-output.log: DBIx::Class::Storage::DBI::_dbh_execute(): DBI Exception: DBD::mysql::st execute failed: Data too long for column 'coded_location_qualifier' at row 1 at /kohadevbox/koha/Koha/Object.pm line 170 It could be good to add something to the Web UI to ask people to consult their sysadmin so they can check the logs for more specifics... -- And maybe the duplicate barcode could be hinted at more although given the code flow I can see how that would be very difficult (without throwing a fatal error to stop the whole import)