UPDATE: Ive reinstalled libreadline6 to no avail. Im still getting the undefined symbol errors gpg: symbol lookup error: /usr/local/lib/libreadline.so.6: undefined symbol: UP

Any help appreciated.

Im trying to update my desktop (I've been away from internet for 6 months) and Im encountering some problems.

apt-get update fails because a public key is unavailable, and apt-get upgrade fails when setting up apt, due to libreadline errors.

Im sure the problem is with my libreadline because during my 6mo without internet Im pretty sure I rebuilt it from source (and encountered other problems in doing so) to try and embed the lua interpreter into a program.

More details on that can be found in my post here: https://stackoverflow.com/questions/22727700/g-undefined-references-with-lua-and-libdl

Here is my apt-get update output.

Its cut down because its recognizing the links and wont let me post because my rep is below 10.

Fetched 316 B in 5s (59 B/s) Reading package lists... Done W: GPG error: https://private-ppa.launchpad.net saucy Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E131728675254D99

My apt-get upgrade

Fetched 360 MB in 3min 28s (1,730 kB/s)
Extracting templates from packages: 100% Preconfiguring packages ... Setting up apt ( ... gpg: symbol lookup error: /usr/local/lib/libreadline.so.6: undefined symbol: UP gpg: symbol lookup error: /usr/local/lib/libreadline.so.6: undefined symbol: UP dpkg: error processing apt (--configure): subprocess installed post-installation script returned error exit status 127 No apport report written because MaxReports is reached already Errors were encountered while processing: apt E: Sub-process /usr/bin/dpkg returned an error code (1)


Try downloading https://packages.debian.org/wheezy/amd64/libreadline6-dbg/download (assuming you're on an x64 system) and installing it using

sudo dpkg -i [filename]

This is the version of libreadline6 available on the official debian repositories.

As for the problem with the bad key, I don't think that's actually a problem - just something to be aware of, that that particular ppa isn't working properly.

  1. Remove the private ppa from your computer, private-ppa's are a commercial product from launchpad and have less stringent requirements from launchpad (typically all PPA uploads need to be signed for public ppa's). Instead of removing you can also add the token [trusted=yes] in your sources.lst on the line that sets up the ppa which will skip the public key check.

  2. Perform apt-get update

  3. Reinstall libreadline through apt

  4. perform upgrade

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