If you have installed Picard in Arch Linux, and you try to explore the CD "CD Lookup", you may get an error like this:

Error While reading CD

Error opening library: libdiscid.so.0 cannot open shared object file: No such file or directory

That is because, you may have not installed libdiscid.so.O, so go ahead and install it from yaour.

yaourt libdisc

You will get something like this:

1 aur/libdiscid 0.2.2-2 (47)
    A Library for creating MusicBrainz DiscIDs
==>  Enter n° (separated by blanks, or a range) of packages to be installed
==>   ----------------------------------------------
==>

Select the package, and yaourt will install it, from there the error will not appear anymore.

If you are installing picard on Ubuntu or Fedora or Debian you will not have this problem, as the library will be installed automatically.