Our CI builds occasionally fail on macOS with the following error:

Error copying file (if different) from "modules/javafx.web/src/main/native/Source/JavaScriptCore/Scripts/wkbuiltins/builtins_generate_separate_header.py" to "modules/javafx.web/build/mac/Release/JavaScriptCore/Scripts/builtins_generate_separate_header.py".
make[2]: *** [JavaScriptCore/Scripts/builtins_generate_separate_header.py] Error 1
make[2]: *** Deleting file `JavaScriptCore/Scripts/builtins_generate_separate_header.py'
make[1]: *** [Source/JavaScriptCore/CMakeFiles/JSCBuiltins.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
...
[ 16%] Linking C static library ../../../lib/libSqliteJava.a
[ 16%] Built target SqliteJava
make: *** [all] Error 2

Originally I had thought this was an error linking libSqliteJava.a, but in digging into a failing build, I see that that library is generated successfully. The error is much earlier in the log, and only after it gets to that point, does the build report the error and abort.