0.98_05 is a release candidate for 0.99. I would say this is the last stable release of Test::More before 1.5.0 but hahahaha I won't say that. https://metacpan.org/release/MSCHWERN/Test-Simple-0.98_05/
There hasn't been a stable release in two years, so there's likely to be code which has wrapped itself around this version. If smokers and Test::* module authors would give it a go and report and problems I'd appreciate that. Here's the changes since 0.98 which might conceivably have an impact. * cmp_ok() will error when it gets a non-comparison operator * isa_ok() and new_ok() default names have changed * like() and unlike() no longer warn about undef * subtests will output their name at the start of the subtest