$ cnf-lookup bleh
cnf-lookup: error while loading shared libraries: libboost_system.so.1.55.0: cannot open shared object file: No such file or directory

$ pacaur -Ss command-not-found
pcr/command-not-found 0.4.5-2 [installed]
In case a command could not be found this utility searches for packages
containing this or a similar command (bash,zsh).
aur/command-not-found 0.6.1-2 (170, 1.49) [installed: 0.4.5-2]
In case a command could not be found this utility searches for packages
containing this or a similar command (bash,zsh).