The latest development releases of Path::Tiny include this whopper in the Changes file:
!!! INCOMPATIBLE CHANGES !!!
The relative() method no longer uses File::Spec's buggy rel2abs method. The new Path::Tiny algorithm should be comparable and passes File::Spec rel2abs test cases, except that it correctly accounts for symlinks. For common use, you are not likely to notice any difference. For uncommon use, this should be an improvement. As a side benefit, this change drops the minimum File::Spec version required, allowing Path::Tiny to be fatpacked if desired.
I sincerely hope that you won't notice the difference – or if you do, it's because Path::Tiny is defending you against a latent symlink bug.
That said, with any change of this magnitude there's a serious risk of breakage. PLEASE, PLEASE, PLEASE, if you use Path::Tiny, I ask that you test your module or application with Path-Tiny-0.081-TRIAL.
$ cpanm --dev Path::Tiny # or $ cpan DAGOLDEN/Path-Tiny-0.081-TRIAL.tar.gz
If you have any problems with it, please open a bug report in the Path::Tiny issue tracker.