Downgrade Glibc

Introduction
Sometimes through over zealous unmasking of packages, can be upgraded to a version not compatible with other bits of software. A particular version of glibc might be needed for certain 3rd party or hardware vendor tools. It could also be for consistency across a fleet of servers so that binary packages are more compatible.

Fail safe
For a fail safe, Modify package.use to enable USE flag for packages  and.

should be installed as well for the tool. Use it to zip up the current glibc installation

The system should still be usable in the event that something goes horribly wrong.

2010.9.28 Note : app-shells/bash now don't have 'static' use.

Prepare the linker
This method is preferred as it doesn't require rebuilding ld.so.cache up-front and doesn't break the build environment.


 * Mask all versions newer than the required version in or just undo whatever it is that you were doing wrong.
 * Get the target version of from Gentoo Binary Packages TinderBox or from a BINHOST.
 * Uncompress the package into


 * Add the following to your file

Downgrade glibc
Save your old /usr/bin/automake (perhaps you will need it in a step!) Since Gentoo will halt when it detects you are downgrading glibc, you need to make portage think that it has not installed glibc yet:
 * Verify that the correct version of glibc will be built: need for good installation FEATURES="-sandbox"
 * Re-emerge your system:


 * Remove or rename your directory and remove the LDFLAGS and CPPFLAGS entries previously added to your.
 * It is safe to reboot your system at this point if other tasks require it.
 * Re-emerge your universe:
 * Re-emerge your universe: