Problem: It is possible to end up with a SIP that has no files

[ross-spencer]

Expected behaviour

When a transfer no-longer has any meaningful files left to process it should fail early.

Current behaviour

In #418 we see a transfer processed by Archivematica through to Job Check transfer directory for objects. The transfer structure looks as follows:

mbox-example$ tree -a
.
└── mbox
    ├── Drafts
    │   └── .mbox
    ├── INBOX
    │   └── .mbox
    ├── Junk
    │   └── .mbox
    ├── processingMCP.xml
    ├── Sent
    │   └── .mbox
    ├── Webmail-old
    │   ├── INBOX
    │   │   └── .mbox
    │   ├── .mbox
    │   └── sent-mail-Oct-2008
    │       └── .mbox
    └── Trash

The hidden files are all removed, leaving just the directories and processingMCP.xml which provides enough structure for Archivematica to attempt to continue processing.

There isn't a lot of feedback for the user when it reaches the final microservice. So between when the hidden files are removed, and when the transfer ostensibly completes, i.e. passes out of Job Check transfer directory for objects with zero error-code, the user might need more information to go on when the SIP doesn't arrive in the Backlog or Ingest tab.

Your environment (version of Archivematica, OS version, etc)

Verified on AM 1.8.

---

For Artefactual use:
Please make sure these steps are taken before moving this issue from Review to Verified in Waffle:

• All PRs related to this issue are properly linked 👍
• All PRs related to this issue have been merged 👍
• Test plan for this issue has been implemented and passed 👍
• Documentation regarding this issue has been written and it has been added to the release notes, if needed 👍

[jorikvankemenade]

@ross-spencer thanks for pointing me in the direction of this ticket. I didn't have time to look into the underlying cause of this particular problem, so this is really helpful!