Currently, setup_chroot.sh is installed as part of the documentation files for scponly, i.e. the dodoc function is called to install it in the ebuild. If one has the nodoc FEATURE specified in make.conf, this file will not be installed. setup_chroot.sh should not be considered documentation as it's a script.
The script doesn't work anyway "as is", so it really is just an example. If you want a working chroot "script, then use 4.6-r1 and emerge --config feature.
Thank you for the information, however, I would request that the file name be renamed with the word example, like make.conf.example, so that this is clear.
As said, it doesn't work out of the box, so it's installed into docs. There's a working pkg_config alternative in the latest version. thanks, closing.
OK, but it's not clear that the script doesn't work to someone installing the package. Also, 4.6 is masked, so someone installing a stable system, with the nodoc feature won't get the script. It's more obvious why the script would fall under docs if the example is appended to setup_chroot.