`unknown function` when referencing stored template "function" in `epub:save_to_disk` plugboard template

[Nathan Dines]

As indicated in the title, when referencing a stored template in the plugboard template for `epub:save_to_disk`, the output ends up including `zero_pad_series: unknown function` inline in the title.

The plugboard template is: `{series}{series_index:zero_pad_series()| [|] - }{title}{#subtitle:|: |}`

The stored template (prefixed with a line of `python:` when applying it in Calibre) can be found at the following link: https://github.com/nathandines/calibre-template-functions/blob/4f78e9edf40caa487ae93b246404af16d6207375/src/calibre_template_functions/zero_pad_series.py

This template works perfectly when using the `any format:KINDLE2` plugboard with the same plugboard template, but does not work with `epub:save_to_disk`. For the sake of testing, I'm also seeing the same issue when using `pdf:save_to_disk`.

Is there perhaps an issue with stored templates being imported when plugboards are being used for `save_to_disk`? I haven't had a chance to dig into the source code of Calibre myself.

Calibre Version: 7.3.0
Operating System: macOS 13.5.2

[Kovid Goyal (kovid)]

Changing the component for this bug.

 assignee
 status

[Kovid Goyal (kovid)]

Fixed in branch master. The fix will be in the next release. calibre is usually released every alternate Friday.