I don’t have much experience building Java apps, but I was able to migrate one of our other apps from batch scripts to Gradle (with functional incremental builds) which taught me what I currently know. I maintain our systems and am in charge of the big picture. I maintain our application build scripts, which includes the gradle.build file that builds one of our primary Jar files. I have stripped it down to the simplest functional configuration which builds the Jar file using the command gradle makeJar. We are using Gradle 8.4 and Bellsoft JDK 17.0.9.

If I introduce even the slightest change to one of our source Java files (ex: add a string variable that is not used), my Jar fails to build at the compileJava task unless I force Gradle to rerun all tasks using the command gradle makeJar --rerun-tasks. I have spent a few days trying to troubleshoot the issue and reviewing the log files (produced by running gradle makeJar --info --debug) without much luck. My build task is failing with the following error (I replaced parts of the paths with asterisks) referencing an untouched Java file and class:

2024-09-04T10:11:46.532-0700 [ERROR] [system.err] C:sandboxv95*srccom*guiGuiFrame.java:2353: error: ribbonTask is not public in AbstractRibbonBand; cannot be accessed from outside package
2024-09-04T10:11:46.533-0700 [ERROR] [system.err]                               this.ribbonTask = null;
2024-09-04T10:11:46.534-0700 [ERROR] [system.err]                                   ^
2024-09-04T10:11:51.673-0700 [ERROR] [system.err] Note: Some input files use or override a deprecated API.
2024-09-04T10:11:51.673-0700 [ERROR] [system.err] Note: Recompile with -Xlint:deprecation for details.
2024-09-04T10:11:51.674-0700 [ERROR] [system.err] Note: Some input files use unchecked or unsafe operations.
2024-09-04T10:11:51.674-0700 [ERROR] [system.err] Note: Recompile with -Xlint:unchecked for details.
2024-09-04T10:11:51.675-0700 [ERROR] [system.err] 1 error
2024-09-04T10:11:56.277-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
2024-09-04T10:11:56.277-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] FAILURE: Build failed with an exception.
2024-09-04T10:11:56.277-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * What went wrong:
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] Execution failed for task ':compileJava'.
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] > Compilation failed; see the compiler error output for details.
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * Try:
2024-09-04T10:11:56.279-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] > Run with --scan to get full insights.
2024-09-04T10:11:56.279-0700 [ERROR] [org.gradle.internal.buildevents.BuildResultLogger]
2024-09-04T10:11:56.279-0700 [ERROR] [org.gradle.internal.buildevents.BuildResultLogger] BUILD FAILED in 19s

I started by removing all the extras in my build.gradle file which are not necessary. These include configurations for our Eclipse project and additional Sync tasks to make sure that static images, JavaScript files, and locale files used by our app use the latest copies. My functional build.gradle file:

/*
 * This file was generated by the Gradle 'init' task.
 *
 * This generated file contains a sample Java Library project to get you started.
 * For more details take a look at the Java Libraries chapter in the Gradle
 * user guide available at https://docs.gradle.org/4.10.2/userguide/java_library_plugin.html
 */
 
apply plugin: 'java'
java {
    sourceCompatibility = JavaVersion.VERSION_17
    targetCompatibility = JavaVersion.VERSION_17
}
compileJava {
    options.compilerArgs << '--add-exports' << 'javafx.graphics/com.sun.glass.ui=ALL-UNNAMED'
}

sourceSets {
    main {
        java {
            srcDir '../../*/src'
        }
    }
}

repositories {
    flatDir {
        dirs '../../*/lib-src'
    }
}
configurations {
    externalLibs
    externalLibsTc
}
dependencies {
    // Add dependent jar files in lib
    implementation fileTree(dir: '../../*/lib', include: ['*.jar','*.zip'], exclude: 'appJar.jar')
    externalLibs fileTree(dir: '../../*/lib', include: ['*.jar','*.zip'], exclude: 'appJar.jar')
    implementation fileTree(dir: '../../*/lib/teamcenter', include: ['*.jar','*.zip'])
    externalLibsTc fileTree(dir: '../../*/lib/teamcenter', include: ['*.jar','*.zip'])

}

// Create a single Jar with all dependencies
task makeJar(type: Jar) {
    archiveBaseName = 'appJar'
    destinationDirectory = file("../../_produce/classes")
    manifest {
        attributes(
            "Manifest-Version": "1.0",
            "Class-Path": configurations.externalLibs.collect { 'lib/' + it.getName() }.join(' ') + ' ' + configurations.externalLibsTc.collect { 'lib/teamcenter/' + it.getName() }.join(' ')
        )
    }

    exclude('com/*/Mulder.class')

    into '', {
        from '../../*/res'
    }
    
    from sourceSets.main.output
}

The above Gradle build script produces our Jar file successfully when I run gradle makeJar --info --debug on a clean area. When I review our log files, I see the following Compiler Args (formatted for readability):

[DEBUG] [org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler] Compiler arguments:
-source 17 

-target 17 

-d C:sandboxv95msvcgradle-*buildclassesjavamain
 
-h C:sandboxv95msvcgradle-*buildgeneratedsourcesheadersjavamain 
-g 

-sourcepath "" 

-proc:none 

-s C:sandboxv95msvcgradle-*buildgeneratedsourcesannotationProcessorjavamain 

-XDuseUnsharedTable=true 

-classpath
C:sandboxv95*libdocking-frames-common.jar;
C:sandboxv95*libdocking-frames-core.jar;
C:sandboxv95*libFilters.jar;
C:sandboxv95*libflamingo.jar;
C:sandboxv95*libgluegen-rt.jar;
C:sandboxv95*libjakarta.xml.bind-api.jar;
C:sandboxv95*libjna-5.5.0.jar;
C:sandboxv95*libjna-platform-5.5.0.jar;
C:sandboxv95*libjogl-all.jar;
C:sandboxv95*libjson-20230618.jar;
C:sandboxv95*libjsoup-1.15.3.jar;
C:sandboxv95*libRadialFx.jar;
C:sandboxv95*libsqlite-jdbc-3.42.0.0.jar;
C:sandboxv95*libswingx-0.9.3.jar;
C:sandboxv95*libtrident.jar;
C:sandboxv95*libunivocity-parsers-2.8.3.jar;
C:sandboxv95*libVectorGraphics2D-0.13.jar;
C:sandboxv95*libxchart-3.6.1.jar;
C:sandboxv95*libteamcenteractivation.jar;
C:sandboxv95*libteamcenteraxis.jar;
C:sandboxv95*libteamcentercommons-discovery-0.2.jar;
C:sandboxv95*libteamcentercommons-logging-1.0.4.jar;
C:sandboxv95*libteamcentercommons-logging.jar;
C:sandboxv95*libteamcenterfsw.jar;
C:sandboxv95*libteamcenterfsw_pkg.jar;
C:sandboxv95*libteamcenterjavax.wsdl_1.6.2.v201012040545.jar;
C:sandboxv95*libteamcenterjaxrpc.jar;
C:sandboxv95*libteamcenterlog4j-api-2.17.1.jar;
C:sandboxv95*libteamcenterlog4j-core-2.17.1.jar;
C:sandboxv95*libteamcentermail.jar;
C:sandboxv95*libteamcenterorg.apache.commons.logging_1.2.0.v20180409-1502.jar;
C:sandboxv95*libteamcentersaaj.jar;
C:sandboxv95*libteamcenterSFC.jar;
C:sandboxv95*libteamcenterTcSoaClient_12000.2.0.jar;
C:sandboxv95*libteamcenterTcSoaCommon_12000.2.0.jar;
C:sandboxv95*libteamcenterteamcenter_sso_applib.jar;
C:sandboxv95*libteamcenterteamcenter_sso_common.jar;
C:sandboxv95*libteamcenterteamcenter_sso_ldapcustom.jar;
C:sandboxv95*libteamcenterteamcenter_sso_webtoolkit.jar;
C:sandboxv95*libteamcenterws-commons-util-1.0.2.jar;
C:sandboxv95*libteamcenterwsdl4j-1.5.1.jar;
C:sandboxv95*libteamcenterxmlrpc-client-3.1.3.jar;
C:sandboxv95*libteamcenterxmlrpc-common-3.1.3.jar;
C:sandboxv95*libteamcenterxmlrpc-server-3.1.3.jar

--add-exports javafx.graphics/com.sun.glass.ui=ALL-UNNAMED 

@sourceCode.txt // I hit a SO character limit, it is originally all my source code files

If I run javac.exe from the command line with the above Compiler Args (added the source files to a file sourceCode.txt to call using @sourceCode.txt), my code compiles without any issues.

I modified the file C:sandboxv95*srccom*productApplication.java by adding a dummy string variable and re-ran my Gradle build script using gradle makeJar --info --debug. My new log file for the incremental build produces the following error:

2024-09-04T10:11:46.532-0700 [ERROR] [system.err] C:sandboxv95*srccom*guiGuiFrame.java:2353: error: ribbonTask is not public in AbstractRibbonBand; cannot be accessed from outside package
2024-09-04T10:11:46.533-0700 [ERROR] [system.err]                               this.ribbonTask = null;
2024-09-04T10:11:46.534-0700 [ERROR] [system.err]                                   ^
2024-09-04T10:11:51.673-0700 [ERROR] [system.err] Note: Some input files use or override a deprecated API.
2024-09-04T10:11:51.673-0700 [ERROR] [system.err] Note: Recompile with -Xlint:deprecation for details.
2024-09-04T10:11:51.674-0700 [ERROR] [system.err] Note: Some input files use unchecked or unsafe operations.
2024-09-04T10:11:51.674-0700 [ERROR] [system.err] Note: Recompile with -Xlint:unchecked for details.
2024-09-04T10:11:51.675-0700 [ERROR] [system.err] 1 error
2024-09-04T10:11:56.277-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
2024-09-04T10:11:56.277-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] FAILURE: Build failed with an exception.
2024-09-04T10:11:56.277-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * What went wrong:
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] Execution failed for task ':compileJava'.
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] > Compilation failed; see the compiler error output for details.
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter]
2024-09-04T10:11:56.278-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] * Try:
2024-09-04T10:11:56.279-0700 [ERROR] [org.gradle.internal.buildevents.BuildExceptionReporter] > Run with --scan to get full insights.
2024-09-04T10:11:56.279-0700 [ERROR] [org.gradle.internal.buildevents.BuildResultLogger]
2024-09-04T10:11:56.279-0700 [ERROR] [org.gradle.internal.buildevents.BuildResultLogger] BUILD FAILED in 19s

It also produces the following Compiler Args:

[DEBUG] [org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler] Compiler arguments:
-source 17

-target 17

-d C:sandboxv95msvcgradle-*buildclassesjavamain

-h C:sandboxv95msvcgradle-*buildgeneratedsourcesheadersjavamain

-g

-sourcepath ""

-proc:none 

-s C:sandboxv95msvcgradle-*buildgeneratedsourcesannotationProcessorjavamain 

-XDuseUnsharedTable=true 

-classpath
C:sandboxv95*libdocking-frames-common.jar;
C:sandboxv95*libdocking-frames-core.jar;
C:sandboxv95*libFilters.jar;
C:sandboxv95*libflamingo.jar;
C:sandboxv95*libgluegen-rt.jar;
C:sandboxv95*libjakarta.xml.bind-api.jar;
C:sandboxv95*libjna-5.5.0.jar;
C:sandboxv95*libjna-platform-5.5.0.jar;
C:sandboxv95*libjogl-all.jar;
C:sandboxv95*libjson-20230618.jar;
C:sandboxv95*libjsoup-1.15.3.jar;
C:sandboxv95*libRadialFx.jar;
C:sandboxv95*libsqlite-jdbc-3.42.0.0.jar;
C:sandboxv95*libswingx-0.9.3.jar;
C:sandboxv95*libtrident.jar;
C:sandboxv95*libunivocity-parsers-2.8.3.jar;
C:sandboxv95*libVectorGraphics2D-0.13.jar;
C:sandboxv95*libxchart-3.6.1.jar;
C:sandboxv95*libteamcenteractivation.jar;
C:sandboxv95*libteamcenteraxis.jar;
C:sandboxv95*libteamcentercommons-discovery-0.2.jar;
C:sandboxv95*libteamcentercommons-logging-1.0.4.jar;
C:sandboxv95*libteamcentercommons-logging.jar;
C:sandboxv95*libteamcenterfsw.jar;
C:sandboxv95*libteamcenterfsw_pkg.jar;
C:sandboxv95*libteamcenterjavax.wsdl_1.6.2.v201012040545.jar;
C:sandboxv95*libteamcenterjaxrpc.jar;
C:sandboxv95*libteamcenterlog4j-api-2.17.1.jar;
C:sandboxv95*libteamcenterlog4j-core-2.17.1.jar;
C:sandboxv95*libteamcentermail.jar;
C:sandboxv95*libteamcenterorg.apache.commons.logging_1.2.0.v20180409-1502.jar;
C:sandboxv95*libteamcentersaaj.jar;
C:sandboxv95*libteamcenterSFC.jar;
C:sandboxv95*libteamcenterTcSoaClient_12000.2.0.jar;
C:sandboxv95*libteamcenterTcSoaCommon_12000.2.0.jar;
C:sandboxv95*libteamcenterteamcenter_sso_applib.jar;
C:sandboxv95*libteamcenterteamcenter_sso_common.jar;
C:sandboxv95*libteamcenterteamcenter_sso_ldapcustom.jar;
C:sandboxv95*libteamcenterteamcenter_sso_webtoolkit.jar;
C:sandboxv95*libteamcenterws-commons-util-1.0.2.jar;
C:sandboxv95*libteamcenterwsdl4j-1.5.1.jar;
C:sandboxv95*libteamcenterxmlrpc-client-3.1.3.jar;
C:sandboxv95*libteamcenterxmlrpc-common-3.1.3.jar;
C:sandboxv95*libteamcenterxmlrpc-server-3.1.3.jar;
C:sandboxv95msvcgradle-*buildclassesjavamain 

--add-exports javafx.graphics/com.sun.glass.ui=ALL-UNNAMED 

@sourceCodeInc.txt // I hit a SO character limit, it is originally a set of source code files needed for the incremental build

If I run javac.exe from the command line with the above Compiler Args (added the source files to a file sourceCodeInc.txt to call using @sourceCodeInc.txt), my code compiles with the same error produced from Gradle incremental build. If I add the file referenced in the error to my sourceCodeInc.txt file (C:sandboxv95*srcorgpushingpixelsflamingoapiribbonAbstractRibbonBand.java) and rerun the same command, my code compiles successfully. I am unsure where to go next, or why the incremental builds. Any guidance will be greatly appreciated, and I hope my lack of experience doesn’t get in the way of fixing the issue.