Locale dependent buildjar code

[hkwi]

hasRecognizedError in (bazel/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/ReducedClasspathJavaLibraryBuilder.java ) parses command line output messages, which varies by system language setting. So build failed on my computer with Japanese locale. I could successfully built the binary from scratch when I changed the system language to English on Windows 10, which requires log off and log on.

Possible fix are:

• add something like "-J-Duser.language=en" to javac arguments, or
• inject arguments like this, or
• change the system locale on every bazel build

[meteorcloudy]

/cc @damienmg How can we fix this properly?

[damienmg]

/cc @eaftan @cushon maintain buildjar so they might know

[ulfjack]

We could disable the reduced classpath. Or you could do that as a workaround.

I think this is the right flag:
--experimental_java_classpath=off

[cushon]

Yep, --experimental_java_classpath=off should work around it.

It would be nice to avoid hard-coding a locale. We might be able to have the reduced classpath compilation emit structured diagnostics, and then do the locale-dependent formatting after checking if fallback was needed.