You could conceivable disable debugging yourself by clearing it. The key is the filename you specified, and the value is the location of the file actually found. The require command uses this array to determine whether a given file has already been included. Setting a value in ENV changes the environment for child processes. Best to be sure and quote it or take a reference to it.
Plumber works too.
See the perlsubs manpage . The warning message is passed as the first argument. The error message is passed as the first argument.