if the compile-output shows something like:
Recompile with -Xlint:deprecation for details
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Then it is time to get to the details of this message:
in Gradle-scripts/build.gradle (Project) include the following line(s):
tasks.withType(JavaCompile) {
options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation"
}
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When you now run the app the root-cause is shown in the output:
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Done