Home » Android » Android proguard issue: path may not be null or empty string. path='null'

Android proguard issue: path may not be null or empty string. path='null'

Posted by: admin May 14, 2020 Leave a comment


Every thing work fine before setting

minifyEnabled true


shrinkResources true

After setting these values, whenever i run project i get this error:

Information:Gradle tasks [:app:assembleProdRelease]
Error:path may not be null or empty string. path='null'
Information:BUILD FAILED
Information:Total time: 23.606 secs
Information:1 error
Information:0 warnings
Information:See complete output in console

What does this error means Error:path may not be null or empty string. path=’null’
Here is build.gradle :

signingConfigs {
            release {
                storeFile file('/home/rishabh/Documents/dekhoJks/release.jks')
                storePassword "XXXXXXX"
                keyAlias "XXXXXXXX"
                keyPassword "XXXXXXXXX"
        buildTypes {
            release {
                minifyEnabled true
                //proguardFiles fileTree(dir: "proguard", include: ["*.pro"]).asList().toArray()
                proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
                shrinkResources true
                signingConfig signingConfigs.release

And i tried to put every single damn thing i can put in proguard.pro :

-optimizationpasses 5
-dump class_files.txt
-printseeds seeds.txt
-printusage unused.txt
-printmapping mapping.txt
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

-keepattributes *Annotation*
-renamesourcefileattribute SourceFile
-keepattributes SourceFile,LineNumberTable
-repackageclasses ''

-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
-dontnote com.android.vending.licensing.ILicensingService

# Explicitly preserve all serialization members. The Serializable interface
# is only a marker interface, so it wouldn't save them.
-keepclassmembers class * implements java.io.Serializable {
    static final long serialVersionUID;
    private static final java.io.ObjectStreamField[] serialPersistentFields;
    private void writeObject(java.io.ObjectOutputStream);
    private void readObject(java.io.ObjectInputStream);
    java.lang.Object writeReplace();
    java.lang.Object readResolve();

# Preserve all native method names and the names of their classes.
-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);

# Preserve static fields of inner classes of R classes that might be accessed
# through introspection.
-keepclassmembers class **.R$* {
  public static <fields>;

# Preserve the special static methods that are required in all enumeration classes.
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);

-keep public class * {
    public protected *;

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
##---------------End: proguard configuration common for all Android apps ----------

#---------------Begin: proguard configuration for support library  ----------
-keep class android.support.v4.app.** { *; }
-keep interface android.support.v4.app.** { *; }
-keep class com.actionbarsherlock.** { *; }
-keep interface com.actionbarsherlock.** { *; }

# The support library contains references to newer platform versions.
# Don't warn about those in case this app is linking against an older
# platform version. We know about them, and they are safe.
-dontwarn android.support.**
-dontwarn com.google.ads.**
##---------------End: proguard configuration for Gson  ----------

##---------------Begin: proguard configuration for Gson  ----------
# Gson uses generic type information stored in a class file when working with fields. Proguard
# removes such information by default, so configure it to keep all of it.
-keepattributes Signature

# For using GSON @Expose annotation
-keepattributes *Annotation*

# Gson specific classes
-keep class sun.misc.Unsafe { *; }
#-keep class com.google.gson.stream.** { *; }

# Application classes that will be serialized/deserialized over Gson
-keep class com.example.model.** { *; }

##---------------End: proguard configuration for Gson  ----------

# If your project uses WebView with JS, uncomment the following
# and specify the fully qualified class name to the JavaScript interface
# class:
#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
#   public *;

-keepclassmembers class android.support.design.internal.BottomNavigationMenuView {
    boolean mShiftingMode;

-dontwarn com.fasterxml.**
-dontwarn okio.**
-dontwarn retrofit2.**
-dontwarn com.fasterxml.jackson.databind.**

# Basic ProGuard rules for Firebase Android SDK 2.0.0+
-keep class com.firebase.** { *; }
-keep class org.apache.** { *; }
-keepnames class com.fasterxml.jackson.** { *; }
-keepnames class javax.servlet.** { *; }
-keepnames class org.ietf.jgss.** { *; }
-dontwarn org.apache.**
-dontwarn org.w3c.dom.**

-dontwarn com.firebase.ui.**

-keepattributes Signature

-dontwarn com.googlecode.mp4parser.**
-dontwarn org.mp4parser.aspectj.runtime.reflect.**
-keep class * implements com.coremedia.iso.boxes.Box { *; }
-dontwarn com.coremedia.iso.boxes.**
-dontwarn com.googlecode.mp4parser.authoring.tracks.mjpeg.**
-dontwarn com.googlecode.mp4parser.authoring.tracks.ttml.**

-keep class com.facebook.** {

But still unable to run my app. Any help where i’m going wrong.

How to&Answers:

Okay got the solution. Just replace your hard codded signing config:

release {
                storeFile file('/home/rishabh/Documents/dekhoJks/release.jks')
                storePassword "XXXXXXX"
                keyAlias "XXXXXXXX"
                keyPassword "XXXXXXXXX"

and instead of that create separate signing.properties file :


enter image description here

and use in your gradle.
Hope it helps!!


Two solutions

  • Use the following classpath. (I was getting this error when i was using the version 2.3.2.)

    classpath 'com.android.tools.build:gradle:2.2.2'

  • Disable the split apk option for a temporary fix if you can’t change the classpath version.