Fix my Gentoo

Introduction
This guide is something I've posted on the forums several times in response to users posting that "nothing works". If your gcc is broken after a, this guide is not for you. You almost certainly need. Be more careful in future.

This guide is for rescuing your install when you can't chroot in, almost nothing seems to work but you have determined that you need some binary packages to fix your system.

It is actually very difficult to break Gentoo so badly, it can't be fixed.

Overview
You need some binary packages to fix your Gentoo.

You might find them on a binhost or tinderbox on the web but they are unlikely to be built for your system, with your USE flags and your CFLAGS.

This guide shows you how to make your own binary packages to use to fix your own system. You will not need another system, a spare partition or even another install.

Prerequsites

 * A working internet connection.
 * A way to boot your broken box with some recovery media, e.g. System Rescue CD, if it won't boot
 * About 20G of free space on your broken install. 5G may do, depending on what you need to build.

Summary
As the bootable install is not working and we need a working install to build binary packages, we need another install. This install need not be bootable.

It is sufficient to be able to chroot into it and run. This rescue install will share some elements with the broken install which saves space and makes things easier in the final steps.

Terminology

 * : Mount your own broken install here.
 * : The new rescue install, it can be anywhere but it needs to be on a hard disk.

The Rescue Install

 * Mount your broken install at so we can use its hard drive space and its.
 * Make a directory at or somewhere with free space:


 * Follow the handbook to fetch a stage3 tarball and untar it to.
 * Do not get a Portage snapshot, we will use the one in the main install.
 * Follow the handbook for all the odds and ends, like copying

Mounts

 * Mount and friends in  just as if you were doing a new install but do not chroot yet.


 * Bind mount the ebuilds to the rescue system:


 * Bind mount the distfiles directory:


 * Bind mount the binary package directory:


 * Copy over to

Now the rescue install has all your own settings too.

Chroot in to rescue install
Follow what the handbook says but into.

Edit /etc/portage/make.conf
Inside of the new working rescue chroot, we need to tell Portage to create and save binary packages of everything we build.

Edit by adding   to.

This causes Portage to save binary tarballs of every package built to.

Building Packages
Two choices:

Quick Package (quickpkg)
If the package needed is part of the stage3, use the tool to make a binary package.

Emerge
will just work. Build something small as a test like then check that the package has appeared in.

More Packages
whatever is needed. will stay around until deleted and it is only a chroot away. Upon return, don't forget to redo the bind mounts.

Installing Binary Packages
After creating binary packages using any of the methods described above, they must be installed somehow to the broken system.

The best method to install binary packages depends on what is broken. The options below are presented in increasing order of risk (least risky first).

Using emerge
This requires that you can chroot into the install to be rescued. If you have managed to remove a part of your toolchain, this should work for you.

will either install the binary tarball and its dependencies or fail if the binaries cannot be found.

Using tar
So you can't chroot in, is not an option. Maybe you removed and you don't have a statically linked ?

Each binary package is like a single package stage3. It has some extra information on the end that Portage uses, which will provoke a warning from that can be safely ignored.

Extracting tar step-by-step method
For safety's sake, unmount the rescue install at.

You may need to unmount all the things mounted inside first.

Sanity checks
Before you issue the command, verify:
 * The install is mounted at
 * You understand the  and   options to . Review the man page if unsure:

Understanding the tar command
This tells to extract, preserving permissions, the file  and Change directory to  before it does anything else.

In fact, the input file name above is not correct. The full path to the tarball is required. Tab completion helps a lot.

Nervous users can add the  option to.

Extract
As described above, unpack the tarball (binary package) into your broken system.

The package is now effectively installed to the broken install. Repeat as necessary for all packages until you can use (see above) instead.

Tidying Up
Once the damage is fixed, delete, or keep it around for next time.

With adequate space, it may be desirable to add  to your   as a regular thing. Then, the tarballs needed for rescuing your system will already exist.

Both and  will grow without limit. Run occasionally to prune them.