Building jdk on OS/X

[Michael Hall]

Seeing the recent comments on build problems I was curious enough to try building on OS/X.
I followed the directions here…
https://hg.openjdk.java.net/jdk-updates/jdk9u/raw-file/tip/common/doc/building.html <https://hg.openjdk.java.net/jdk-updates/jdk9u/raw-file/tip/common/doc/building.html>
I get errors like…

=== Output from failing command(s) repeated here ===
* For target buildtools_buildtools_hotspot_tools_classes__the.BUILD_TOOLS_HOTSPOT_batch:
warning: [path] bad path element "/Library/Frameworks/BSF4ooRexx.framework/Classes/bsf4ooRexx-v641-20190830-bin.jar": no such file or directory
warning: [path] bad path element "/Applications/OpenOffice.app/Contents/program/classes/ridl.jar": no such file or directory
warning: [path] bad path element "/Applications/OpenOffice.app/Contents/program/classes/jurt.jar": no such file or directory
warning: [path] bad path element "/Applications/OpenOffice.app/Contents/program/classes/juh.jar": no such file or directory
warning: [path] bad path element "/Applications/OpenOffice.app/Contents/program/classes/unoil.jar": no such file or directory
warning: [path] bad path element "/Applications/OpenOffice.app/Contents/program": no such file or directory
warning: [path] bad path element "/Library/Frameworks/BSF4ooRexx.framework/Classes/bsf4ooRexx-v641-20191126-bin.jar": no such file or directory
error: warnings found and -Werror specified
1 error
7 warnings

First try I moved the concerned application (OpenOffice.app) and framework (BSF4ooRexx.framework) out of the way. The error persisted. Seeing that make clean removed make but not config files I removed the jdk directory and cloned the repository again and the error persisted. 
After spending some time trying to determine how to change compile options to eliminate the 'warnings as error' it occurred to me that these are not compile errors and no compiler option change will probably be a fix.

My questions are…

Where is these files having been present persisted?

Why does building the jdk have anything to do with them?