unexpected PLT reloc: Meerkat -> Natty upgrade, system unusable

[mcelrath]

Binary package hint: update-manager

Upon using the update-manager to upgrade from 10.10 to 11.04, the upgrade aborts in the middle, and afterwards the system is unusable. All programs give shared library errors: 'ls: error while loading shared libraries: /lib/x86_64-linux-gnu/libc.so.6: unexpected PLT reloc type 0x25'.

This appears to be due to an incompatibility between libc6 and 10.10 binaries. After the new Natty libc6 is installed (2.13-0ubuntu13_amd64) all 10.10 binaries fail in this way.

I cannot easily gather information from the system, as it is not unusable. But I will post what I find after I have rebuilt the system booting off a USB stick...

[mcelrath (bob+launchpad)]

This appears to be due to the following symlink: /lib/ld-linux-x86-64.so.2 which was not properly updated by the libc6 package. I had on my system: ld-linux-x86-64.so.2 -> libc-2.6.1.so.

As libc-2.6.1.so is from 2007, this appears to be cruft left from Gutsy (?) days that was not removed. (This system has been upgraded through all Ubuntu releases since at least Gutsy).

The package libc6_2.13-0ubuntu13_amd64.deb *does* contain the proper symlink. I do not know why it was not installed.
Upon chrooting and reinstalling, the above link was *restored* to the bad old libc6-2.6.1.so by the package installation itself. Removing this file allowed libc6 to install properly. (Note that I first renamed it to libc6-2.6.1.so.bak but the libc6 install scripts STILL created this erroneous link to it).