Thanks for checking David.
The test failure above is with java -version:Âopenjdk version "9.0.4" (linux).
After seeing it passes for you with "1.8.0_182" (OSX), I tried in another machine with "1.8.0_181" (linux) and it works.
I found a possible explanation here , which links to the java spec:
"In JDK 9, the Unicode Consortium's Common Locale Data Repository (CLDR) data is enabled as the default locale data, so that you can use standard locale data without any further action.
In JDK 8, although CLDR locale data is bundled with the JRE, it isnât enabled by default.
Code that uses locale-sensitive services such as date, time, and number formatting may produce different results with the CLDR locale data.
Not sure yet of the real impact in JGit beyond breaking one test. There is a way to make java 9 use the JRE locale instead of CLDR, but I would rather update the code to make it version-independent.