Cannot get purge to work

I would like to delete all copies of a file that was backed up from my Linux /home directory to a Dropbox backend. Let’s say the file is called unwanted_file.txt, so I have run the following in terminal:

duplicati-cli purge dropbox://home?authid=MyAuthID unwanted_file.txt --dbpath=/home/user/.config/Duplicati/12345678901234567890.sqlite --dry-run

but I get the following error:

ErrorID: PurgeWouldRemoveEntireFileset
Refusing to purge 138852 files from fileset with ID 1, as that would remove the entire fileset.

I don’t understand this. The file has only been backed up 3 times, and this numbers suggests the command wants to delete all files in my /home backup. Trying something similar in the GUI commandline and the process seems to simply never end; I let it run for over 2 hours and it still said “Running …” with --dry-run.

How can I simply delete these 3 file backups?

Does it help if you prefix the filename like this: --include=unwanted_file.txt

No, I tried it and got the exact same error:

ErrorID: PurgeWouldRemoveEntireFileset
Refusing to purge 138852 files from fileset with ID 1, as that would remove the entire fileset.

What version are you using? Version 2.0.4.31 fixed a bug involving purging on Linux that would remove too many files.

In my test environment, the purge command did not give any output.

When using the commandline tools from the GUI, you have to specify the passphrase (--passphrase="mypassword"), because there is no way to provide it when the operation is running.

Duplicati stores the complete path for each file and folder and it expects a complete path as input for operations like purge. Wildcards are allowed.
Replace unwanted_file.txt with "*/unwanted_file.txt" (including double quotes).