You say to avoid using $^O, but then recommend using File::Spec
I took the original advice as another "don't reinvent the wheel" caution. I.e. look for a module that already does things portably rather than try to write it again from scratch. It's a thought that applies more for program authors than for module authors, who do need to concern themselves with OS-specific behaviors if they're planning on distributing things to CPAN.
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