Unable to build android project with maven (androi

Strange behavior, sometimes I can package my project, most of the time I cannot. The problem happens in android:dex:

$ mvn clean android:dex
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Test 0.0.1
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.3:clean (default-clean) @ test ---
[INFO] Deleting file set: /home/danny/workspace/test/target (included: [**], excluded: [])
[INFO] 
[INFO] --- android-maven-plugin:3.3.2:dex (default-cli) @ test ---
[INFO] /usr/lib/jvm/java-6-sun-1.6.0.26/jre/bin/java [-Xmx1024M, -jar, /home/danny/.bin/android-sdk-linux/platform-tools/lib/dx.jar, --dex, --output=/home/danny/workspace/test/target/classes.dex, /home/danny/workspace/test/target/classes]
[INFO] 
[INFO] UNEXPECTED TOP-LEVEL EXCEPTION:
[INFO] java.lang.RuntimeException: /home/danny/workspace/test/target/classes: file not found
[INFO]  at com.android.dx.util.FileUtils.readFile(FileUtils.java:55)
[INFO]  at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:134)
[INFO]  at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
[INFO]  at com.android.dx.command.dexer.Main.processOne(Main.java:418)
[INFO]  at com.android.dx.command.dexer.Main.processAllFiles(Main.java:329)
[INFO]  at com.android.dx.command.dexer.Main.run(Main.java:206)
[INFO]  at com.android.dx.command.dexer.Main.main(Main.java:174)
[INFO]  at com.android.dx.command.Main.main(Main.java:91)
[INFO] 1 error; aborting
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.914s
[INFO] Finished at: Sun Oct 07 20:17:03 CEST 2012
[INFO] Final Memory: 7M/88M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal com.jayway.maven.plugins.android.generation2:android-maven-plugin:3.3.2:dex (default-cli) on project test: MojoExecutionException: ANDROID-040-001: Could not execute: Command = /bin/sh -c cd /home/danny/workspace/test && /usr/lib/jvm/java-6-sun-1.6.0.26/jre/bin/java -Xmx1024M -jar /home/danny/.bin/android-sdk-linux/platform-tools/lib/dx.jar --dex --output=/home/danny/workspace/test/target/classes.dex /home/danny/workspace/test/target/classes, Result = 1 -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

I cannot find any information on this... My pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
    http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>
    <packaging>apk</packaging>
    <artifactId>test</artifactId>
    <groupId>com.example</groupId>
    <name>Test</name>
    <version>0.0.1</version>

    <dependencies>
        <dependency>
            <artifactId>android</artifactId>
            <groupId>com.google.android</groupId>
            <scope>provided</scope>
            <version>2.2.1</version>
        </dependency>
        <dependency>
            <artifactId>junit</artifactId>
            <groupId>junit</groupId>
            <scope>test</scope>
            <version>4.10</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>android-maven-plugin</artifactId>
                <configuration>
                    <assetsDirectory>src/main/assets</assetsDirectory>
                    <resourceDirectory>src/main/resources</resourceDirectory>
                    <sdk>
                        <platform>8</platform>
                    </sdk>
                </configuration>
                <extensions>true</extensions>
                <groupId>com.jayway.maven.plugins.android.generation2</groupId>
                <version>3.3.2</version>
            </plugin>    
        </plugins>
    </build>

</project>

EDIT

Running mvn package results in:

$ mvn package
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Test 0.0.1
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- android-maven-plugin:3.3.2:generate-sources (default-generate-sources) @ test ---
[INFO] ANDROID-904-002: Found aidl files: Count = 0
[INFO] ANDROID-904-002: Found aidl files: Count = 0
[INFO] /home/danny/.bin/android-sdk-linux/platform-tools/aapt [package, -m, -J, /home/danny/workspace/test/target/generated-sources/r, -M, /home/danny/workspace/test/AndroidManifest.xml, -S, /home/danny/workspace/test/src/main/resources, --auto-add-overlay, -A, /home/danny/workspace/test/src/main/assets, -I, /home/danny/.bin/android-sdk-linux/platforms/android-8/android.jar]
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ test ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 8 resources
[INFO] skip non existing resourceDirectory /home/danny/workspace/test/target/generated-sources/extracted-dependencies/src/main/resources
[INFO] 
[INFO] --- maven-compiler-plugin:2.5.1:compile (default-compile) @ test ---
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 3 source files to /home/danny/workspace/test/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /home/danny/workspace/test/src/main/java/com/example/test/gui/MainActivity.java:[17,18] package R does not exist
[ERROR] /home/danny/workspace/test/src/main/java/com/example/test/gui/MainActivity.java:[26,29] package R does not exist
[INFO] 2 errors 
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.960s
[INFO] Finished at: Sun Oct 07 22:40:35 CEST 2012
[INFO] Final Memory: 13M/86M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.5.1:compile (default-compile) on project test: Compilation failure: Compilation failure:
[ERROR] /home/danny/workspace/test/src/main/java/com/example/test/gui/MainActivity.java:[17,18] package R does not exist
[ERROR] /home/danny/workspace/test/src/main/java/com/example/test/gui/MainActivity.java:[26,29] package R does not exist
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

回答1:

Well, I can tell you that, based on that log, your builder is deleting all the files in a folder right before it tries to dex that folder - thus, the dex fails as there is nothing there. However, I have no idea why this is happening as I don't see you having invoked the maven-clean-plugin anywhere. I have seen similar issues happen where builds work if you call mvn clean, then mvn install, but will NOT work if you call mvn clean install; however, I have only seen this in large custom builds where people are calling the clean plugin themselves. However, it's possible it may also help your situation, even though I can't see what's causing it...

EDIT: Sorry, it's still early for me. The problem isn't the clean, the problem is that the compiler plugin is never running. After the clean you will generally have any resources you need getting generated, then your code gets compiled, and THEN the classes will get dexed. You are never generating your .class files, so there is nothing to dex.

回答2:

The generated R file used the package declaration com.example.test (which is the groupId of my project) and I tried to access it in the class com.example.test.gui.MainActivity. So I needed to import com.example.test.R explicitly.