perl -V lists the hardcoded initial value for @INC. The error message includes @INC as it was when the require was executed. @INC can be modified directly, or by using env var PERL5LIB, env var PERLLIB, module lib or the command line option -I (via command line, shebang or env var PERLOPTS).
Comment on Re^5: Can't locate IO/Scalar.pm in @INC (@INC contains: /opt/rocks/lib/perl5/5.8.8/