Gentoo Installation – How to Install Non-Ebuild Programs

I'm pretty sure this should be doable using Gentoo Prefix.

Usually, Gentoo's Portage installs in the root of the filesystem hierarchy, '/'. On systems other than Gentoo Linux, this usually results in problems, due to conflicts of software packages, unless the OS is adapted like Gentoo/FreeBSD. Instead, Gentoo Prefix installs with an offset, allowing to install in another location in the filesystem hierarchy, hence avoiding conflicts. Next to this offset, Gentoo Prefix runs unprivileged, meaning no root user or rights are required to use it.

Using portage you can do this with package.env. The right place to look for the documentation is http://dev.gentoo.org/~zmedico/portage/doc/portage.html#config-bashrc-ebuild-phase-hooks. Basically the way you use it is as follows. First you create (assuming standard setup without custom ROOT) a file in /etc/portage/env. For example, you can create a file /etc/portage/env/paxmark

#paxmark

#Set this to what you need it to be
PAXFLAGS="-p"

post_src_install() {
  find "${INSTALL}" -type x -print0 |xargs -0 -n 1 paxctl $PAXFLAGS
}

Then for all packages you want this to apply to you add an entry to /etc/portage/package.env :

#package.env example for paxmark
sys-apps/gcc paxmark

This will apply the paxmark script to the package that has it specified. Alternatively you can also create a /etc/portage/bashrc script for global overrides (be very careful with that).

A general warning though, as you can add pre and post hooks to all phases this can be dangerous. Be careful with what you do as all your packages that use the hook have now become no more robust than your hook script. (The above example for pax marking should be fine).