<path/to>/jdk/open/src/java.desktop/unix/native/libawt_xawt/xawt/XToolkit.c:695:9: error: ignoring return value of function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result]
 695 | write ( AWT_WRITEPIPE, &wakeUp_char, 1 );
   | ^~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

Seems to not occur in release builds for some reason. Looking at warning options in the build, I didn't see any differences that seemed relevant.

Code in question hasn't been touched in forever.