ADDITIONAL SYSTEM INFORMATION :
Java 8 all the way up to 15

A DESCRIPTION OF THE PROBLEM :
FilerOutputStream, which can be used by annotation processors to write source files, extends from FilterOutputStream without overwriting the write(byte[], offset, length) method. This means that content written to this stream is written to disk one byte at a time, greatly slowing down builds.


CUSTOMER SUBMITTED WORKAROUND :
Use JavaFileObject.openWriter instead, which does not suffer from this performance problem.

FREQUENCY : always