On 01/15/15 15:57, Sl�vek Banko wrote

> You can instead use an alternative apt source 'preliminary-stable-builds',
> which already reflect on change libical1 => libical1a.

Fantastic. I inserted this repository into sources.list:
     deb http://mirror.xcer.cz/trinity-sb jessie deps-r14 main-r14

now APT successfully computes the dependency tree and prompts me for 
confirmation to proceed with installation.

However, I also found an alternative repository hosting the same Trinity 
release for Jessie, namely:

deb 
http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity-nightly-builds/ubuntu 
jessie main

Should I prefer one to the other, or are both equivalent?

-- Davide