`java.awt.HeadlessException` on Linux

Bắt đầu bằng cách tái hiện bash gradlew importer và đọc các điểm bắt đầu trong stack trace là VortexUi.java, ImportMetWizard.java và VortexWizard.java. So sánh hành vi đó với các Gradle task hiện có và kết quả build trên Java 11 so với Java 21. Được xem là hoàn tất khi hành vi của importer trên Linux không có X11 DISPLAY được xác định và lỗi được báo cáo được một build hoặc test đã xác minh bao phủ.

bash gradlew build -x test

Build fails with java11, but it builds with java 21.

But running bash gradlew importer:run gives:

    Cannot locate tasks that match 'importer:run' as task 'run' not found in project ':importer'.

So, I tried bash gradlew tasks and saw there is "importer" and "run" separately,

Trying bash gradlew importer fails with HeadlessException:

> Task :vortex-ui:importer FAILED
Exception in thread "main" java.awt.HeadlessException: 
No X11 DISPLAY variable was set,
or no headful library support was found,
but this program performed an operation which requires it,

        at java.desktop/java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:166)
        at java.desktop/java.awt.Window.<init>(Window.java:553)
        at java.desktop/java.awt.Frame.<init>(Frame.java:428)
        at java.desktop/java.awt.Frame.<init>(Frame.java:393)
        at java.desktop/javax.swing.JFrame.<init>(JFrame.java:180)
        at mil.army.usace.hec.vortex.ui.VortexWizard.<init>(VortexWizard.java:28)
        at mil.army.usace.hec.vortex.ui.ImportMetWizard.<init>(ImportMetWizard.java:47)
        at mil.army.usace.hec.vortex.ui.VortexUi.main(VortexUi.java:25)

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':vortex-ui:importer'.
> Process 'command '/usr/lib/jvm/java-21-openjdk/bin/java'' finished with non-zero exit value 1

P.S. Results from bash gradlew build -x test

> Task :copyJre
Execution optimizations have been disabled for task ':copyJre' to ensure correctness due to the following reasons:
  - Gradle detected a problem with the following location: '/home/gaurav/executables/Vortex-0.11.9/bin/jre'. Reason: Task ':copyJre' uses this output of task ':getNatives' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.6/userguide/validation_problems.html#implicit_dependency for more details about this problem.

> Task :copyNatives
Execution optimizations have been disabled for task ':copyNatives' to ensure correctness due to the following reasons:
  - Gradle detected a problem with the following location: '/home/gaurav/executables/Vortex-0.11.9/bin'. Reason: Task ':copyNatives' uses this output of task ':getNatives' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.6/userguide/validation_problems.html#implicit_dependency for more details about this problem.

> Task :zipLinux
Execution optimizations have been disabled for task ':zipLinux' to ensure correctness due to the following reasons:
  - Gradle detected a problem with the following location: '/home/gaurav/executables/Vortex-0.11.9/build/distributions/vortex-0.1.0-dev.0.uncommitted'. Reason: Task ':zipLinux' uses this output of task ':copyVortexUi' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.6/userguide/validation_problems.html#implicit_dependency for more details about this problem.
  - Gradle detected a problem with the following location: '/home/gaurav/executables/Vortex-0.11.9/build/distributions/vortex-0.1.0-dev.0.uncommitted'. Reason: Task ':zipLinux' uses this output of task ':copyLicense' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.6/userguide/validation_problems.html#implicit_dependency for more details about this problem.
  - Gradle detected a problem with the following location: '/home/gaurav/executables/Vortex-0.11.9/build/distributions/vortex-0.1.0-dev.0.uncommitted'. Reason: Task ':zipLinux' uses this output of task ':copyStartScripts' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.6/userguide/validation_problems.html#implicit_dependency for more details about this problem.
  - Gradle detected a problem with the following location: '/home/gaurav/executables/Vortex-0.11.9/build/distributions/vortex-0.1.0-dev.0.uncommitted'. Reason: Task ':zipLinux' uses this output of task ':copyNatives' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.6/userguide/validation_problems.html#implicit_dependency for more details about this problem.
  - Gradle detected a problem with the following location: '/home/gaurav/executables/Vortex-0.11.9/build/distributions/vortex-0.1.0-dev.0.uncommitted'. Reason: Task ':zipLinux' uses this output of task ':copyJre' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.6/userguide/validation_problems.html#implicit_dependency for more details about this problem.
  - Gradle detected a problem with the following location: '/home/gaurav/executables/Vortex-0.11.9/build/distributions/vortex-0.1.0-dev.0.uncommitted'. Reason: Task ':zipLinux' uses this output of task ':copyRuntimeLibs' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.6/userguide/validation_problems.html#implicit_dependency for more details about this problem.

Deprecated Gradle features were used in this build, making it incompatible with Gradle 8.0.

You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.

See https://docs.gradle.org/7.6/userguide/command_line_interface.html#sec:command_line_warnings

Execution optimizations have been disabled for 3 invalid unit(s) of work during this build to ensure correctness.
Please consult deprecation warnings for more details.

BUILD SUCCESSFUL in 15s
17 actionable tasks: 8 executed, 9 up-to-date

I also tried to compile it installing gradle 8.4 but it didn't work. So all of the above is when gradle isn't installed in the system.