A bit late to the party, but if the root cause is that the package hasn't finished building yet, it would be nice to see that noted in the error message.
I still had to google "signing key fingerprint does not exist" to figure out what was going on. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to software-properties in Ubuntu. https://bugs.launchpad.net/bugs/968756 Title: apt-add-repository fails while adding ppa if signing_key_fingerprint does not exist Status in “software-properties” package in Ubuntu: Fix Released Bug description: sudo apt-add-repository ppa:floaty-devs/ppa You are about to add the following PPA to your system: More info: https://launchpad.net/~floaty-devs/+archive/ppa Press [ENTER] to continue or ctrl-c to cancel adding it Exception in thread Thread-1: Traceback (most recent call last): File "/usr/lib/python2.7/threading.py", line 551, in __bootstrap_inner self.run() File "/usr/lib/python2.7/dist-packages/softwareproperties/ppa.py", line 95, in run self.add_ppa_signing_key(self.ppa_path) File "/usr/lib/python2.7/dist-packages/softwareproperties/ppa.py", line 117, in add_ppa_signing_key "--recv", signing_key_fingerprint]) File "/usr/lib/python2.7/subprocess.py", line 493, in call return Popen(*popenargs, **kwargs).wait() File "/usr/lib/python2.7/subprocess.py", line 679, in __init__ errread, errwrite) File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child raise child_exception TypeError: execv() arg 2 must contain only strings ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: apt 0.8.16~exp12ubuntu6 ProcVersionSignature: Ubuntu 3.2.0-20.33-generic 3.2.12 Uname: Linux 3.2.0-20-generic x86_64 ApportVersion: 1.95-0ubuntu1 Architecture: amd64 Date: Fri Mar 30 01:38:13 2012 EcryptfsInUse: Yes InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120328) ProcEnviron: TERM=xterm LANG=sk_SK.UTF-8 SHELL=/bin/bash SourcePackage: apt UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/968756/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp