Test suite comparing with ICU failed on master branch

[harendra-kumar]

The test comparing with icu, closed by #46 has failed again on master branch CI:

Failures:

  test/Properties.hs:64:9: 

  1) Comparing random strings with ICU...

       Falsified (after 2753 tests and 6 shrinks):

         NFKD

         "\127340"

I think we can put a specific test for this codepoint to get a predictable failure. Not sure why it failed with icu-66 as well, is that ppa reliable? On my machine with icu-65 it passes.

[Bodigrim]

Probably ppa is unreliable :(

I checked on my machine with icu-66, unicode-transforms passes 10000000 tests.

Dunno, at this point I'd go ahead as is. Alternatively we can run to ICU tests only if icu is modern enough, guarding relevant properties by t_normalizeCompareICU "\127340" check.

[harendra-kumar]

Which distribution are you running, how did you install icu66? libicu66 on travis/focal does not seem to be normalizing "\127340" correctly.

[Bodigrim]

I do not have an Ubuntu machine, unfortunately. On my mac I obtained ICU via brew install icu4c.