Build to Linux desktop by "gradle -PCOMPILE_TARGETS=x86egl" fails with error:

Deprecated dynamic property: "compilePrefix" on "root project 'rt'", value: "".

FAILURE: Build failed with an exception.

* Where:
Script '/home/elina/work/8-u20-clean/rt/buildSrc/x86egl.gradle' line: 59

* What went wrong:
A problem occurred evaluating script.
> No signature of method: java.lang.String.exists() is applicable for argument types: () values: []
  Possible solutions: wait(), expand(), toList(), execute(), expand(), toList()

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED