passing -XDignore.symbol.file to compiler with maven

[Carnë Draug <carandraug+dev@gmail.com>]

Hi

I'm trying to package JLargeArrays [1] to Debian which requires
passing the '-XDignore.symbol.file' option to the compiler [2].  This
package uses maven and 'mvn package' works fine in Debian Stretch.

However, the Debian package I prepared [3] failed to build until I set
the maven.compiler.fork option [4].  I found online that maven would
silently discard '-XD' flags unless fork is set but upstream does not
have that set and it builds fine in Debian.  Could someone explain to
me why?  This is my first Java Debian package and I'm probably missing
something pretty obvious.

Thank you
Carnë

[1] https://gitlab.com/ICM-VisLab/JLargeArrays
[2] https://gitlab.com/ICM-VisLab/JLargeArrays/blob/develop/pom.xml#L95
[3] https://github.com/carandraug/debian-libjlargearrays-java
[4] https://github.com/carandraug/debian-libjlargearrays-java/commit/ef0d5bfa