Description
The current code suggests the plugin supports toolchains, given the output if the line below, but this is not actually the case. Seems like a copy-paste thing.
getLog().debug("Toolchains are ignored, 'executable' parameter is set to " + executable) ).
The compiler plugin has a pretty complex determine-the-javac logic, while the javafx-plugin simply uses the java.exe on the system path. This difference can manifest itself when "clean javafx:run" is started from Eclipse; the compiler plugin is using the JDK configured in Eclipse's project (say Java 15), while javafx:run is using the java.exe with which Eclipse was started (say Java 11). You'll then get a class version exception.
You can set the executable in the javafx-plugin manually, but the javafx-plugin can also correctly support toolchains and thus use the same jdk as the compiler does.