Traté de usar Proguard en mi proyecto de Android, configuré Proguard usando la línea de comando 'android update project / path / to / project' y el archivo proguard.cfg fue creado en el directorio raíz del proyecto. (En mi Eclipse con Android 2.3 sdk, cuando creo un nuevo proyecto, el archivo proguard.cfg no se crea automáticamente, así que tengo que agregarlo manualmente usando la línea de comandos).

Cuando exporto el proyecto, recibo los siguientes errores

    [2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.io.Buffer
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields$Field
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields$Field
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields$Field
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.Address
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.io.Buffer
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.Address
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields$Field
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.HttpRequestAdapter: can't find referenced class org.mortbay.jetty.HttpFields
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.CommonsLoggingLoggerFactory: can't find referenced class org.apache.commons.logging.LogFactory
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.CommonsLoggingLoggerFactory: can't find referenced class org.apache.commons.logging.LogFactory
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLoggerFactory: can't find referenced class org.slf4j.LoggerFactory
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLoggerFactory: can't find referenced class org.slf4j.LoggerFactory
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.jetty.JettyOAuthConsumer: can't find referenced class org.mortbay.jetty.client.HttpExchange
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLoggerFactory: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLoggerFactory: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.signature.OAuthMessageSigner: can't find referenced class org.apache.commons.codec.binary.Base64
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.signature.OAuthMessageSigner: can't find referenced class org.apache.commons.codec.binary.Base64
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.signature.OAuthMessageSigner: can't find referenced class org.apache.commons.codec.binary.Base64
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.signature.OAuthMessageSigner: can't find referenced class org.apache.commons.codec.binary.Base64
[2011-02-06 09:02:49 - TestProject] Warning: oauth.signpost.signature.OAuthMessageSigner: can't find referenced class org.apache.commons.codec.binary.Base64
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.SLF4JLogger: can't find referenced class org.slf4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Level
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Level
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject] Warning: twitter4j.internal.logging.Log4JLogger: can't find referenced class org.apache.log4j.Logger
[2011-02-06 09:02:49 - TestProject]       You should check if you need to specify additional program jars.
[2011-02-06 09:02:49 - TestProject] Warning: there were 59 unresolved references to classes or interfaces.
[2011-02-06 09:02:49 - TestProject]          You may need to specify additional library jars (using '-libraryjars'),
[2011-02-06 09:02:49 - TestProject]          or perhaps the '-dontskipnonpubliclibraryclasses' option.
[2011-02-06 09:02:49 - TestProject] java.io.IOException: Please correct the above warnings first.
[2011-02-06 09:02:49 - TestProject]     at proguard.Initializer.execute(Initializer.java:308)
[2011-02-06 09:02:49 - TestProject]     at proguard.ProGuard.initialize(ProGuard.java:210)
[2011-02-06 09:02:49 - TestProject]     at proguard.ProGuard.execute(ProGuard.java:85)
[2011-02-06 09:02:49 - TestProject]     at proguard.ProGuard.main(ProGuard.java:499)

Estos mensajes de error apuntan a cuatro frascos externos utilizados en mi proyecto

(.classpath)

<classpathentry kind="lib" path="/Users/lorensiuswlt/Android/android-sdk-mac_x86/libs/Twitter/signpost-commonshttp4-1.2.1.1.jar"/>
        <classpathentry kind="lib" path="/Users/lorensiuswlt/Android/android-sdk-mac_x86/libs/Twitter/signpost-core-1.2.1.1.jar"/>
        <classpathentry kind="lib" path="/Users/lorensiuswlt/Android/android-sdk-mac_x86/libs/Twitter/signpost-jetty6-1.2.1.1.jar"/>
        <classpathentry kind="lib" path="/Users/lorensiuswlt/Android/android-sdk-mac_x86/libs/Twitter/twitter4j-core-2.1.6.jar"/>

Aquí está mi archivo proguard.cfg

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService

-keepclasseswithmembernames class * {
    native <methods>;
}

-keepclasseswithmembernames class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembernames class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

He probado algunas soluciones encontradas en la web agregando la opción '-libraryjars', por ejemplo:

-libraryjars /Users/lorensiuswlt/Android/android-sdk-mac_x86/libs/Twitter/twitter4j-core-2.1.6.jar

Pero no ayudará.

¿Alguna solución?