When a label is created, it is allowed (since no error is shown) to use the forward slash (/). Unfortunately, though, if it is used the page of that label is impossible to view.
For example, by creating the coding/javascript label, both https://example.com/bookmarks/labels/coding%2Fjavascript and https://example.com/bookmarks/labels/coding/javascript return a 404 error.
Solution
Alright, I found the culprit :) (it wasn't the database but nginx)
Readeck's documentation incorrectly asks to put proxy_pass http://127.0.0.1:8000/; while it must be proxy_pass http://127.0.0.1:8000; (no trailing slash).
Description of the bug
When a label is created, it is allowed (since no error is shown) to use the forward slash (
/
). Unfortunately, though, if it is used the page of that label is impossible to view.For example, by creating the
coding/javascript
label, bothhttps://example.com/bookmarks/labels/coding%2Fjavascript
andhttps://example.com/bookmarks/labels/coding/javascript
return a 404 error.Solution
From https://codeberg.org/readeck/readeck/issues/277#issuecomment-2418764