Command line calibredb set_metadata problem

[Nedan]

Hi,

when you add a book to a series you can tell calibre which book number it is. Imagine i have 200 files and i add them to the database and enter a series. Then each book will have in the book field the number 1. i want change this but not with manual way in the gui. It is tiresome to select the book, press E, click on the book field and enter the number 200 times.

So, the idea i had is the following one: Writing a bash script which will do this automatically. That wshould be the final result BUT:
I tried to write the metadata with calibredb set_metadata ID /path/to/opf-file.
For that i had changed the following line in the opf-file from:

<meta name="calibre:series_index" content="1">

to

<meta name="calibre:series_index" content="25">

and wrote the data into database with calibredb set_metadata ID /path/to/opf-file

It worked well, except that the command would not write the 25 into the database. Instead it turned out that the 1 was still there.
What have i done wrong? Is there a way to change the book number that way?

[kovidgoyal]

most likely a bug, open a ticket and attach the opf file you used