On Windows-7 using fresh gradle 2.3 install. GRADLE_HOME is set. GRADLE_USER_HOME setting is irrelevant:
$ gradle -v --debug --stacktrace
16:17:57.747 [DEBUG] [org.gradle.internal.nativeintegration.services.NativeServices] Unable to initialize native-platform. Failure: net.rubygrapefruit.platform.NativeException: Failed to initialise native integration. caused by: java.lang.UnsatisfiedLinkError: net.rubygrapefruit.platform.internal.jni.NativeLibraryFunctions.getVersion()I 16:17:57.772 [ERROR] [org.gradle.BuildExceptionReporter] 16:17:57.775 [ERROR] [org.gradle.BuildExceptionReporter] FAILURE: Build failed with an exception. 16:17:57.775 [ERROR] [org.gradle.BuildExceptionReporter] 16:17:57.775 [ERROR] [org.gradle.BuildExceptionReporter] * What went wrong: 16:17:57.776 [ERROR] [org.gradle.BuildExceptionReporter] com.sun.jna.Native.sizeof(I)I 16:17:57.776 [ERROR] [org.gradle.BuildExceptionReporter] 16:17:57.777 [ERROR] [org.gradle.BuildExceptionReporter] * Exception is: 16:17:57.777 [ERROR] [org.gradle.BuildExceptionReporter] java.lang.UnsatisfiedLinkError: com.sun.jna.Native.sizeof(I)I 16:17:57.778 [ERROR] [org.gradle.BuildExceptionReporter]
at com.sun.jna.Native.sizeof(Native Method) 16:17:57.778 [ERROR] [org.gradle.BuildExceptionReporter]
at com.sun.jna.Native.(Native.java:110) 16:17:57.778 [ERROR] [org.gradle.BuildExceptionReporter]
at org.fusesource.jansi.internal.Kernel32.(Kernel32.java:33) 16:17:57.778 [ERROR] [org.gradle.BuildExceptionReporter]
at org.fusesource.jansi.WindowsAnsiOutputStream.(WindowsAnsiOutputStream.java:47) 16:17:57.779 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.internal.nativeintegration.console.WindowsConsoleDetector.getConsole(WindowsConsoleDetector.java:28) 16:17:57.779 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.logging.internal.ConsoleConfigureAction.execute(ConsoleConfigureAction.java:38) 16:17:57.779 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.logging.internal.ConsoleConfigureAction.execute(ConsoleConfigureAction.java:29) 16:17:57.779 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.logging.internal.OutputEventRenderer.attachProcessConsole(OutputEventRenderer.java:75) 16:17:57.779 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.logging.internal.DefaultLoggingManager.attachProcessConsole(DefaultLoggingManager.java:163) 16:17:57.780 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:204) 16:17:57.780 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:169) 16:17:57.780 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33) 16:17:57.780 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22) 16:17:57.781 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.Main.doAction(Main.java:33) 16:17:57.781 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45) 16:17:57.781 [ERROR] [org.gradle.BuildExceptionReporter]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 16:17:57.781 [ERROR] [org.gradle.BuildExceptionReporter]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 16:17:57.782 [ERROR] [org.gradle.BuildExceptionReporter]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 16:17:57.782 [ERROR] [org.gradle.BuildExceptionReporter]
at java.lang.reflect.Method.invoke(Method.java:606) 16:17:57.782 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:54) 16:17:57.782 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:35) 16:17:57.782 [ERROR] [org.gradle.BuildExceptionReporter]
at org.gradle.launcher.GradleMain.main(GradleMain.java:23) 16:17:57.783 [ERROR] [org.gradle.BuildExceptionReporter]