uberjar: second build fails

[rvansa]

Describe the bug
With uberjar enabled, the second time I run mvn install it fails with:

[ERROR]     [error]: Build step io.quarkus.deployment.pkg.steps.JarResultBuildStep#buildUberJar threw an exception: java.lang.IllegalStateException: java.nio.file.FileAlreadyExistsException: META-INF/services/org.eclipse.microprofile.context.spi.ContextManagerProvider
[ERROR]     at io.quarkus.deployment.ExtensionLoader$1.execute(ExtensionLoader.java:949)
[ERROR]     at io.quarkus.builder.BuildContext.run(BuildContext.java:415)
[ERROR]     at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
[ERROR]     at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:2011)
[ERROR]     at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1535)
[ERROR]     at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1426)
[ERROR]     at java.lang.Thread.run(Thread.java:748)
[ERROR]     at org.jboss.threads.JBossThread.run(JBossThread.java:479)
[ERROR] Caused by: java.nio.file.FileAlreadyExistsException: META-INF/services/org.eclipse.microprofile.context.spi.ContextManagerProvider
[ERROR]     at com.sun.nio.zipfs.ZipFileSystem.newOutputStream(ZipFileSystem.java:516)
[ERROR]     at com.sun.nio.zipfs.ZipPath.newOutputStream(ZipPath.java:790)
[ERROR]     at com.sun.nio.zipfs.ZipFileSystemProvider.newOutputStream(ZipFileSystemProvider.java:285)
[ERROR]     at java.nio.file.Files.newOutputStream(Files.java:216)
[ERROR]     at io.quarkus.deployment.pkg.steps.JarResultBuildStep.copyCommonContent(JarResultBuildStep.java:407)
[ERROR]     at io.quarkus.deployment.pkg.steps.JarResultBuildStep.buildUberJar(JarResultBuildStep.java:230)
[ERROR]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[ERROR]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[ERROR]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[ERROR]     at java.lang.reflect.Method.invoke(Method.java:498)
[ERROR]     at io.quarkus.deployment.ExtensionLoader$1.execute(ExtensionLoader.java:940)
[ERROR]     ... 7 more

mvn clean install works as usual.

Environment (please complete the following information):

• Output of uname -a or ver: 5.2.17-200.fc30.x86_64 #1 SMP Mon Sep 23 13:42:32 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
• Output of java -version: openjdk version "1.8.0_222"
• GraalVM version (if different from Java):
• Quarkus version or git rev: 0.26.1

Additional context
The build also outputs a lot of warnings like:

[WARNING] [io.quarkus.deployment.pkg.steps.JarResultBuildStep] Duplicate entry META-INF/quarkus-extension.json entry from io.quarkus:quarkus-resteasy-jackson::jar:0.26.1(compile) will be ignored. Existing file was provided by io.quarkus:quarkus-resteasy-common::jar:0.26.1(compile)

This should be avoided.

[jaikiran]

FWIW - this appears to be a bug in Java itself. The Files.newOutputStream states that:

<p> This method opens or creates a file in exactly the manner specified
     * by the {@link #newByteChannel(Path,Set,FileAttribute[]) newByteChannel}
     * method with the exception that the {@link StandardOpenOption#READ READ}
     * option may not be present in the array of options. If no options are
     * present then this method works as if the {@link StandardOpenOption#CREATE
     * CREATE}, {@link StandardOpenOption#TRUNCATE_EXISTING TRUNCATE_EXISTING},
     * and {@link StandardOpenOption#WRITE WRITE} options are present. In other
     * words, it opens the file for writing, creating the file if it doesn't
     * exist, or initially truncating an existing {@link #isRegularFile
     * regular-file} to a size of {@code 0} if it exists.

So this error shouldn't have happened with the code we have.

I gave this a quick test with Java 8 and it indeed fails with the exception. However, if I move to Java 11 (11.0.5 to be precise) the exception no longer happens and things work fine. So it looks like it got fixed in some recent version.

[geoand]

I was indeed surprised to see this reported error, however we should work around it.

[jaikiran]

however we should work around it.

Agreed.

[geoand]

I'll open a PR later on today, haven't started working on it yet.

[jaikiran]

FWIW - this appears to be a bug in Java itself.

https://bugs.openjdk.java.net/browse/JDK-8233015