I have created an android application that uses android-support-v4.jar.
Now when I add an android library to this project I get this error when building:
UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoIcsImpl;
[2012-11-08 16:02:31 - ShoppingApp Android] Conversion to Dalvik format failed with error 1
The library I'm trying to add is Facebook SDK, which also happens to use android-support-v4.jar.
Only solution for this error I found was removing library from one of build paths, but I can't do it - all options all disabled when I select this jar.
Here is full error trace:
UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoIcsImpl;
at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:123)
at com.android.dx.dex.file.DexFile.add(DexFile.java:163)
at com.android.dx.command.dexer.Main.processClass(Main.java:486)
at com.android.dx.command.dexer.Main.processFileBytes(Main.java:455)
at com.android.dx.command.dexer.Main.access$400(Main.java:67)
at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:394)
at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)
at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)
at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
at com.android.dx.command.dexer.Main.processOne(Main.java:418)
at com.android.dx.command.dexer.Main.processAllFiles(Main.java:329)
at com.android.dx.command.dexer.Main.run(Main.java:206)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.android.ide.eclipse.adt.internal.build.DexWrapper.run(DexWrapper.java:180)
at com.android.ide.eclipse.adt.internal.build.BuildHelper.executeDx(BuildHelper.java:703)
at com.android.ide.eclipse.adt.internal.build.builders.PostCompilerBuilder.build(PostCompilerBuilder.java:577)
at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:728)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:199)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:321)
at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:396)
at org.eclipse.core.internal.resources.Project$1.run(Project.java:618)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2344)
at org.eclipse.core.internal.resources.Project.internalBuild(Project.java:597)
at org.eclipse.core.internal.resources.Project.build(Project.java:124)
at com.android.ide.eclipse.adt.internal.project.ProjectHelper.doFullIncrementalDebugBuild(ProjectHelper.java:1000)
at com.android.ide.eclipse.adt.internal.launch.LaunchConfigDelegate.launch(LaunchConfigDelegate.java:147)
at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:855)
at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:704)
at org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java:1047)
at org.eclipse.debug.internal.ui.DebugUIPlugin$8.run(DebugUIPlugin.java:1251)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
[2012-11-08 16:02:31 - ShoppingApp Android] Dx 1 error; aborting
[2012-11-08 16:02:31 - ShoppingApp Android] Conversion to Dalvik format failed with error 1
The build process checks the checksum of every jar and raises this error if the jar is found twice and the jars have different checksums.
This means you have the same library twice but two different versions of the jar file, which doesn't make sense.
If you added a library project, you don't need the support library in your app, you can delete it as it is inherited from the project library.
You might want to update the jar of the support library into the library project.
Edit: you don't play with the build path anymore, your libraries folders should be "libs" and it will appear in the project as "Android dependencies". Then you remove the jar from your libs folder of your app, and maybe update the one from the library project.
This error means that you have some classes included more than once in your build. I've solved quite the same problem with mvn dependencies in eclipse by unchecking "Export maven decencies" in Project configuration/Java Build Path/Export.
Related
I tried to build the AOSP following the android parent site "https://source.android.com/source/building-running.html".
Steps :
a) source build/envsetup.sh
b) lunch
c) I selected "full-eng"
d) Then make -j4
I have configured the cchache as well. Some error with switch.pm also I got, then I resolved it as well but after this error I am not getting anything. I can see the userdata.img and ramdisk.img file in the out folder. I dont see the system.img file.
And it throws this error. Anythigh else I missed, let me know.
I got this error :
UNEXPECTED TOP-LEVEL EXCEPTION:
com.android.dx.util.ExceptionWithContext: Index: 1, Size: 2
at com.android.dx.util.ExceptionWithContext.withContext(ExceptionWithContext.java:46)
at com.android.dx.dex.cf.CfTranslator.processMethods(CfTranslator.java:344)
at com.android.dx.dex.cf.CfTranslator.translate0(CfTranslator.java:134)
at com.android.dx.dex.cf.CfTranslator.translate(CfTranslator.java:87)
at com.android.dx.command.dexer.Main.processClass(Main.java:487)
at com.android.dx.command.dexer.Main.processFileBytes(Main.java:459)
at com.android.dx.command.dexer.Main.access$400(Main.java:67)
at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:398)
at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)
at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)
at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
at com.android.dx.command.dexer.Main.processOne(Main.java:422)
at com.android.dx.command.dexer.Main.processAllFiles(Main.java:333)
at com.android.dx.command.dexer.Main.run(Main.java:209)
at com.android.dx.command.dexer.Main.main(Main.java:174)
at com.android.dx.command.Main.main(Main.java:91)
Caused by: java.lang.IndexOutOfBoundsException: Index: 1, Size: 2
at java.util.ArrayList.RangeCheck(ArrayList.java:547)
at java.util.ArrayList.remove(ArrayList.java:387)
at com.android.dx.ssa.Dominators.compress(Dominators.java:136)
at com.android.dx.ssa.Dominators.eval(Dominators.java:160)
at com.android.dx.ssa.Dominators.run(Dominators.java:229)
at com.android.dx.ssa.Dominators.make(Dominators.java:90)
at com.android.dx.ssa.DomFront.run(DomFront.java:90)
at com.android.dx.ssa.SsaConverter.placePhiFunctions(SsaConverter.java:298)
at com.android.dx.ssa.SsaConverter.convertToSsaMethod(SsaConverter.java:52)
at com.android.dx.ssa.Optimizer.optimize(Optimizer.java:99)
at com.android.dx.ssa.Optimizer.optimize(Optimizer.java:73)
at com.android.dx.dex.cf.CfTranslator.processMethods(CfTranslator.java:273)
... 14 more
...while processing onQueryComplete (ILjava/lang/Object;Lcom/android/internal/telephony/CallerInfo;)V
...while processing com/android/phone/CallNotifier.class
What am I missing here? Please help me out as I can am not able to proceed further then this state.
Environment :
Linux Ubuntu 14.04
JDK 1.6.0
AOSP branch for 4.2.2
I have a problem.
I have an application builded with monodroid libraries.
Version of android sdk 4.0.3 (API level 15), GoogleAdMobAdsSdk v.6.4.1.
I made separated project to import adsdk to xamarin, add to Metadata.xml attributes. This project compiling without errors. But when i have a reference to this project from my monodroid application i get an error:
/Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets: Error: Tool exited with code: 3. Output:
UNEXPECTED TOP-LEVEL ERROR:
java.lang.OutOfMemoryError: Java heap space
at com.android.dx.util.IntList.growIfNeeded(IntList.java:274)
at com.android.dx.util.IntList.add(IntList.java:217)
at com.android.dx.util.LabeledList.addLabelIndex(LabeledList.java:96)
at com.android.dx.util.LabeledList.set(LabeledList.java:184)
at com.android.dx.rop.code.BasicBlockList.set(BasicBlockList.java:77)
at com.android.dx.ssa.back.SsaToRop.convertBasicBlocks(SsaToRop.java:260)
at com.android.dx.ssa.back.SsaToRop.convert(SsaToRop.java:124)
at com.android.dx.ssa.back.SsaToRop.convertToRopMethod(SsaToRop.java:70)
at com.android.dx.ssa.Optimizer.optimize(Optimizer.java:102)
at com.android.dx.ssa.Optimizer.optimize(Optimizer.java:73)
at com.android.dx.dex.cf.CfTranslator.processMethods(CfTranslator.java:273)
at com.android.dx.dex.cf.CfTranslator.translate0(CfTranslator.java:134)
at com.android.dx.dex.cf.CfTranslator.translate(CfTranslator.java:87)
at com.android.dx.command.dexer.Main.processClass(Main.java:487)
at com.android.dx.command.dexer.Main.processFileBytes(Main.java:459)
at com.android.dx.command.dexer.Main.access$400(Main.java:67)
at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:398)
at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)
at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)
at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
at com.android.dx.command.dexer.Main.processOne(Main.java:422)
at com.android.dx.command.dexer.Main.processAllFiles(Main.java:333)
at com.android.dx.command.dexer.Main.run(Main.java:209)
at com.android.dx.command.dexer.Main.main(Main.java:174)
at com.android.dx.command.Main.main(Main.java:91)
(MyMegaMonoDroidApplication)
Where is my error?
ThnX.
Please specify the Java Heap Size = 1G (or 512M might help you).
Here is how to do that for Xamarin Studio https://stackoverflow.com/a/24833518/883738
In Visual Studio you should do that in the Android project properties
When I try to compile (not execute) one of my projects, I recently get the following error:
Tool /usr/bin/java execution started with arguments: -jar /Applications/android-sdk-mac_x86/platform-tools/lib/dx.jar --no-strict --dex --output=obj/Debug/android/bin/classes.dex obj/Debug/android/bin/classes /Developer/MonoAndroid/usr/lib/mandroid/platforms/android-8/mono.android.jar FlurryAnalytics/Jars/FlurryAgent.jar Jars/android-support-v4.jar
UNEXPECTED TOP-LEVEL ERROR:
java.lang.OutOfMemoryError: Java heap space
at com.android.dx.rop.code.RegisterSpecSet.<init>(RegisterSpecSet.java:49)
at com.android.dx.rop.code.RegisterSpecSet.mutableCopy(RegisterSpecSet.java:383)
at com.android.dx.ssa.LocalVariableInfo.mutableCopyOfStarts(LocalVariableInfo.java:169)
at com.android.dx.ssa.LocalVariableExtractor.processBlock(LocalVariableExtractor.java:104)
at com.android.dx.ssa.LocalVariableExtractor.doit(LocalVariableExtractor.java:90)
at com.android.dx.ssa.LocalVariableExtractor.extract(LocalVariableExtractor.java:56)
at com.android.dx.ssa.SsaConverter.convertToSsaMethod(SsaConverter.java:50)
at com.android.dx.ssa.Optimizer.optimize(Optimizer.java:99)
at com.android.dx.ssa.Optimizer.optimize(Optimizer.java:73)
at com.android.dx.dex.cf.CfTranslator.processMethods(CfTranslator.java:273)
at com.android.dx.dex.cf.CfTranslator.translate0(CfTranslator.java:134)
at com.android.dx.dex.cf.CfTranslator.translate(CfTranslator.java:87)
at com.android.dx.command.dexer.Main.processClass(Main.java:487)
at com.android.dx.command.dexer.Main.processFileBytes(Main.java:459)
at com.android.dx.command.dexer.Main.access$400(Main.java:67)
at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:398)
at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)
at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)
at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
at com.android.dx.command.dexer.Main.processOne(Main.java:422)
at com.android.dx.command.dexer.Main.processAllFiles(Main.java:333)
at com.android.dx.command.dexer.Main.run(Main.java:209)
at com.android.dx.command.dexer.Main.main(Main.java:174)
at com.android.dx.command.Main.main(Main.java:91)
Other projects build as expected. I think I need to increase the heap size for this java build step? But how?
There is an option in Xamarin Studio to increase the Java Heap Size.
Project Options -> Android Build -> Advanced -> Java Heap Size.
This suggestion did the trick:
$ export _JAVA_OPTIONS="-Xmx1g"
$ /Applications/MonoDevelop.app/Contents/MacOS/MonoDevelop
I have a few jar files in my project. Flurry, Maps and Newtonsoft... aparently this is enough to bomb the build.
Thanks to the awesome Xamarin Support team for their quick response and pointing out the solution! They are working on reducing the needed memory footprint for external jars.
When using ActionBarSherlock and ViewPagerIndicator at the same time I am getting the below error; from what I've read - it's caused due to conflicting/duplicate libraries in the two.
One solution was to have ABS rely on VPI (Or the other way around, I tried both) but this still gave me the same error even after a clean and rebuild. Right now I'm just working in two separate projects so I can get my work done - but I'd like to combine them obviously ha. Help would be much appreciated!
[2012-04-19 00:39:20 - MashableReader] Dx
UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat;
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:123)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.dex.file.DexFile.add(DexFile.java:163)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.command.dexer.Main.processClass(Main.java:486)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.command.dexer.Main.processFileBytes(Main.java:455)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.command.dexer.Main.access$400(Main.java:67)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:394)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.command.dexer.Main.processOne(Main.java:418)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.command.dexer.Main.processAllFiles(Main.java:329)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.dx.command.dexer.Main.run(Main.java:206)
[2012-04-19 00:39:20 - MashableReader] Dx at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[2012-04-19 00:39:20 - MashableReader] Dx at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
[2012-04-19 00:39:20 - MashableReader] Dx at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
[2012-04-19 00:39:20 - MashableReader] Dx at java.lang.reflect.Method.invoke(Unknown Source)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.ide.eclipse.adt.internal.build.DexWrapper.run(DexWrapper.java:180)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.ide.eclipse.adt.internal.build.BuildHelper.executeDx(BuildHelper.java:702)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.ide.eclipse.adt.internal.build.builders.PostCompilerBuilder.build(PostCompilerBuilder.java:646)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:728)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:199)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:321)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:396)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.resources.Project$1.run(Project.java:618)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2344)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.resources.Project.internalBuild(Project.java:597)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.resources.Project.build(Project.java:124)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.ide.eclipse.adt.internal.project.ProjectHelper.doFullIncrementalDebugBuild(ProjectHelper.java:1000)
[2012-04-19 00:39:20 - MashableReader] Dx at com.android.ide.eclipse.adt.internal.launch.LaunchConfigDelegate.launch(LaunchConfigDelegate.java:147)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:854)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:703)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java:928)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.debug.internal.ui.DebugUIPlugin$8.run(DebugUIPlugin.java:1132)
[2012-04-19 00:39:20 - MashableReader] Dx at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)
[2012-04-19 00:39:20 - MashableReader] Dx 1 error; aborting
[2012-04-19 00:39:20 - MashableReader] Conversion to Dalvik format failed with error 1
UPDATE WITH ANSWER:
Alright - as the answer below gets at, the issue was the dependency resolution in the Eclipse ADT. Basically my solution was to make the ViewPagerIndicator rely on ActionBarSherlock (Meaning, in the VPI properties, I add ABS to the project like you would for a regular project - for those of you who might be thinking backwards). I still had issues with that when I was getting errors in my code saying some of the methods couldn't be overridden - this part is because you have the wrong imports, so delete all your imports and CRTL+SHIFT+O (Quick import resolution) and select all the ones from the android.support.v4 packages and you should be all good on that. But then I still ran into the original Dalvik issue - to fix this I had to go into the actual folder where my VPI library was and delete the support jar from the /libs folder to stop it from grabbing it - then all set :)
Yes, the problem is both ActionBarSherlock and ViewPagerIndicator use libs/android-support-v4.jar dependency.
The simplest solution is upgrade your work station to latest Android SDK and Eclipse ADT plugin version (at least r17), as this situation is automatically handled by the SDK now (since r17), see the r17 changelog:
Dependency resolution
When a project references two Library projects that both require the same jar file, the build system has to detect and resolve the duplication.
Also Note that since r17, all jar file under libs folder are automatically populated to project's classpath, you don't need manually add them to project's build path anymore, also mentioned in the r17 changelog:
Projects have source folders, as well as Library Project and jar file dependencies. With no other setup needed than adding Library Projects as a dependency in project.properties, a project’s classpath is automatically populated with:
The content of the project’s libs/*.jar
The output of the Library Projects.
The Library Projects’ libs/*.jar
Hope this helps.
I'm on the latest version of ADT, SDK etc and it still has this problem - it still doesn't seem to know which support library to use from which dependent library etc.
TJ's solution does work but I used an alternate approach.
My solution was the following:
Went into each library project and main application project that references the library and deleted the libs/android-support-v4.jar reference
Went back into each project and dragged the android-support-v4.jar from the filesystem (on my Mac, I store the SDK in my documents folder: Users//Documents/Android/android-sdk-mac_x86/extras/android/compatibility/v4/android-support-v4.jar) onto the libs folder and choose to LINK to the jar instead of copying it into the project.
Now all my projects reference the same .jar file on my filesystem and if I update the support library in the future (via the Android SDK Manager), the .jar will be updated and the projects in turn will pull in the latest jar.
So updating the support library should not break anything and allow you to be on the latest version.
I have a static java library(classes.jar) file which has source code common to a Android Library Project and the dependent app which is calling this Android Library project.
I'm using ant env to compile the code on linux machine.
But when I include this jar file under libs folders of both ALP and App, it gives the following compilation error :
[dex] Converting compiled files and external libraries into classes.dex...
[dx]
[dx] UNEXPECTED TOP-LEVEL EXCEPTION:
[dx] java.lang.IllegalArgumentException: already added: Lcom/android/test/ProgramCache;
[dx] at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:123)
[dx] at com.android.dx.dex.file.DexFile.add(DexFile.java:163)
[dx] at com.android.dx.command.dexer.Main.processClass(Main.java:486)
[dx] at com.android.dx.command.dexer.Main.processFileBytes(Main.java:455)
[dx] at com.android.dx.command.dexer.Main.access$400(Main.java:67)
[dx] at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:394)
[dx] at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)
[dx] at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)
[dx] at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
[dx] at com.android.dx.command.dexer.Main.processOne(Main.java:418)
[dx] at com.android.dx.command.dexer.Main.processAllFiles(Main.java:329)
[dx] at com.android.dx.command.dexer.Main.run(Main.java:206)
[dx] at com.android.dx.command.dexer.Main.main(Main.java:174)
[dx] at com.android.dx.command.Main.main(Main.java:95)
[dx] 1 error; aborting
How would I solve this problem of common jar?
Hopefully I won't mix up rules about building android projects in eclipse with building projects in ant with the android toolchain... (And with any luck, you won't have to do both like I do :))
Any jar files in the /libs folders of android shared libraries are automatically included by the command line android build tools. While I can't remember if they are copied on disk, or only added to the build path during compilation, it should suffice to simply remove the jar from App/libs.
Another word of advice when dealing with this problem, ant clean early and often. Its very easy to accidentally build some classes into one of your project jars and then have conflicts later.