Re: Data updates in debian packages

[Ole Streicher <olebole@debian.org>]

Paul Wise <pabs@debian.org> writes:
> On Sat, Oct 29, 2016 at 8:45 PM, Ole Streicher wrote:
>> The package in question (casacore) wants them in a specific format "CASA
>> table" (which is uniformly used within that package), and dependent
>> packages access this in that specific format. The only way would be to
>> create this table from another leap second table (instead of our current
>> source usno.navy.mil), and to update this every time the original table
>> is updated (which I would have to learn how to do this).
>
> You can use dpkg triggers to update files in response to packages
> updating other files.

I tried this, namely (the source package and has only one binary
package):

-------------------- debian/triggers ------------------
interest /usr/share/zoneinfo/leap-seconds.list
---------------------------8<--------------------------

-------------------- debian/postinst ------------------
#!/bin/sh

set -e

case "$1" in
    triggered|configure)
        casacore-update-tai_utc
	;;
    abort-upgrade|abort-remove|abort-deconfigure)
	;;
    *)
        echo "postinst called with unknown argument \`$1'" >&2
        exit 1
	;;
esac

#DEBHELPER#
---------------------------8<--------------------------

However, I now get the following error when I try to update tzdata:

dpkg: cycle found while processing triggers:
 chain of packages whose triggers are or may be responsible:
  casacore-data-tai-utc -> casacore-data-tai-utc
 packages' pending triggers which are or may be unresolvable:
  casacore-data-tai-utc: /usr/share/zoneinfo/leap-seconds.list
dpkg: error processing package casacore-data-tai-utc (--configure):
 triggers looping, abandoned
Errors were encountered while processing:
 casacore-data-tai-utc

What is my mistake here?

Best regards

Ole