The openjfx build attempts to build decora-sse even on Linux, which is not set up to support it. Here is the error:

jar:
...
    [jar] Building jar: openjfx/rt/decora-sse/dist/decora-sse.jar

check-native:

compile-native:

BUILD FAILED
openjfx/build.xml:45: The following error occurred while executing this line:
openjfx//rt/build.xml:97: The following error occurred while executing this line:
openjfx//rt/decora-sse/build-common.xml:39: The following error occurred while executing this line:
openjfx//rt/decora-sse/build-common.xml:27: The following error occurred while executing this line:
java.io.FileNotFoundException: openjfx/rt/decora-sse/build-linux.xml (No such file or directory)