cldr-apps TestAll.java fails with current data in the file tools/java/org/unicode/cldr/util/data/europe unless an assert is disabled in the function parseSeconds.
That function gets called with in = "-1:00" and allowNegative = false.
This line was changed (un-commented out) in changeset  (scroll to the bottom):
I introduced the problem. I'm going to fix the issue soon.
This is introduced by . I should have put "rearguard" version of tzdata in CLDR tool, but I put the standard version that includes negative DST offset rules.
I downloaded and unzipped https://web.cs.ucla.edu/~eggert/tz/release/2019a/tzdata2019a-rearguard.tar.gz and confirmed its "europe" file matches the one in changeset  by Yoshito, and has the problematic line commented out.