Possibly a ‘proguard.cfg’ problem. Does it include any ‘-injars’? If your project includes another project as a library, jars can be processed twice. Could you post your ‘proguard.cfg’?
Extract from http://proguard.sourceforge.net/index.html#manual/troubleshooting.html:
Your input jars contain multiple resource files with the same name.
ProGuard continues copying the resource files as usual, skipping any
files with previously used names. Once more, the warning may be an
indication of some problem though, so it’s advisable to remove the
duplicates. A convenient way to do so is by specifying filters on the
input jars. There is no option to switch off these warnings.
OPTION #1:
As you can’t post your ‘-injars’, check if they include either ‘android-support-v13.jar’ or the library included in your project which itself also includes ‘android-support-v13.jar’.
Assuming you are building with Ant inside IntelliJ IDEA, you mustn’t add -injars, -outjars, or -libraryjars options; the Ant script already does that for you.
OPTION #2:
Although the warnings are harmless, a clean build is a happy build, so try:
and
https://gist.github.com/paulpv/4439012
OPTION #3:
Include (!META-INF/MANIFEST.MF) after each ‘-injars’ command
-injars library.jar(!META-INF/MANIFEST.MF)
OPTION #4: Android Proguard Duplicate Definition
Fixed this by moving the 3rd party libraries to another directory, in
my case ‘lib’. Then added-injars lib/jmdns.jarto the proguard.cfg file.
OPTION #5: Android – Proguard duplicate zip entry error
If your Proguard config file includes the following line, remove it:
-injars bin/classes
OPTION #6: Android obfuscate app using proguard keeps obfuscating library jars – or is it?
I found another way to make Proguard leave library jars alone was to
ask it to preserve their package names, eg:-keep class javax.** { *; }
-keep class org.** { *; }
-keep class twitter4j.** { *; }
OPTION #7:
A weird solution (deleting META-INF folder in src folder) to something similar here.