Why there are so many binary packages missing?

[Yuri]

Matthew Seaman wrote:
> Yuri wrote:
>> I am seeing this for a long time. If I use 'portupgrade -aPP' 
>> (packages only) there is a very large percentage of packages missing.
>> Upgrading becomes many times faster when binary packages available 
>> are available.
>
> Missing binary packages are due in the main to three reasons:
>
>   * Restrictive licensing terms
>
>   * Ports that through bugs, or otherwise, fail to successfully generate
>     a binary package.  Some ports (eg. sysutils/screen up until about 2
>     months ago 
> (http://www.freebsd.org/cgi/cvsweb.cgi/ports/sysutils/screen/Makefile.diff?r1=1.77;r2=1.78)) 
>
>     just won't package successfully, even if they build, install and run
>     perfectly well.
>
>   * The port has a dependency on another port that failed for reason 
> (2).      Because the ports build cluster installs the dependencies of 
> the port it
>     is currently trying to build from binary packages, any lower level 
> port
>     that fails will prevent packages being built for anything that 
> depends on
>     it.
>

Thank you for this information.

Let's put aside #1. There are probably very few of those.
It still seems strange: on my system all of the ports that I need build 
ok. Why would the port build successfully, but would fail to generate a 
binary package? Isn't packaging just gzipping resulting binaries with 
some minor additions?
Also why wouldn't the cluster build and install a port, once the package 
fails? This way the #3 item is eliminated completely. Since it looks 
like there is much more likely to build a port then a binary package.

Yuri