oraenv in 11.2.0.3 on hp-ux itanium issue sh: @: Parameter not set.

$ . oraenv
sh: @: Parameter not set.

https://forums.oracle.com/forums/thread.jspa?threadID=2139644

Our unix administratos have set user profiles with:

set -u

which will exit any script if you try to use an uninitialised variable.