Using "[ 192.168.60.0/24+ ]” works, however from the documentation I read the following regarding the `include` operator: 

Special operators include (~, !~) for "is (not) element of a set" operation - it can be used on […] on prefix and prefix (returning true if first prefix is more specific than second one)

In my case I have "import where net ~ [ 192.168.60.0/24 ] ;”, which should be true because prefix 192.168.60.10/32 is more specific than 192.168.60.0/24. That statement, in fact, is true on Bird 1.6.x. and, without the array ("import where net ~ 192.168.60.0/24 ;”), on Bird 2.0.x. 
Why do my networks get filtered out then? 

Thanks, 
Carlo

On 27 Jun 2018, at 16:20, Ondrej Zajicek <santiago@crfreenet.org> wrote:

On Wed, Jun 27, 2018 at 04:11:17PM +0200, Carlo Rengo wrote:
My bad, I’ve posted the log outputs in the opposite order. The first output is referred to the second configuration (the one that makes us of the array).

Hi, it works like it worked in 1.6.x branch. Prefix set [ 192.168.60.0/24 ]
matches only the 192.168.60.0/24 prefix. You have to use prefix set
[ 192.168.60.0/24+ ] to match 192.168.60.0/24 and longer prefixes.

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Ondrej 'Santiago' Zajicek (email: santiago@crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."