gossip is missing a dependency, it depends on libtasn1 (note that the last 1 is not the letter l, but the number one) and it is not included in the dependency list.

As you can see:

[glenn@polaris ~]$ gossip&
gossip: error while loading shared libraries: libtasn1.so.2: cannot open shared object file: No such file or directory
[1] 26933
[1] Exit 127 gossip
[glenn@polaris ~]$ su
Password:
[root@polaris glenn]# pacman -S libtasn1

Targets: libtasn1-0.2.13-1

Total Package Size: 0.1 MB

Proceed with upgrade? [Y/n]

checking package integrity... done.
loading package data... done.
checking for file conflicts... done.
installing libtasn1... done.
[root@polaris glenn]# exit
exit
[glenn@polaris ~]$ gossip&
gossip: /usr/lib/libgnutls.so.11: no version information available (required by /usr/lib/libloudmouth-1.so.0)
[1] 26938
[glenn@polaris ~]$