Android java.lang.VerifyError Rejecting class * because it failed compile-time verification (declaration of * appears in /data/app/**-1/base.apk)

VerifyErrorTest.java

/*
Notes:
gradleVersion = '2.14.1'
com.android.tools.build:gradle:2.2.3
compileSdkVersion 25
buildToolsVersion "25.0.2"
minSdkVersion 15
targetSdkVersion 25
*/

    private interface Region {
        public String getName();
    }

    public enum Country {
        US, CA
    }

    public enum USState implements Region {
        NEWYORK;

        @Override
        public String getName(){
            return name();
        }
    }

    public enum CanadianTerritory implements Region {
        ONTARIO;

        @Override
        public String getName(){
            return name();
        }
    }

    private Country country = Country.US;

    // Throws runtime VerifyError complaining about compile-time verification, even though
    // both enums very clearly implement the Region interface
    private Region[] getRegions(){
        if(country == Country.CA)
            return CanadianTerritory.values();
        else
            return USState.values();
    }

    // Will NOT throw the VerifyError, but compiler warns of redundant casting
    private Region[] getRegions(){
        if(country == Country.CA)
            return (Region[]) CanadianTerritory.values();
        else
            return (Region[]) USState.values();
    }

    // Throws runtime VerifyError complaining about compile-time verification, even though
    // both enums very clearly implement the Region interface
    private Region[] getRegions(){
        switch(country){
            case CA: return CanadianTerritory.values();
            case US:
            default: return USState.values();
        }
    }

    // Throws VerifyError with "bad method" message
    private List<Region> getRegions(){
        List<Region> regions = new ArrayList<Region>();
        
        if(country == Country.CA)
            regions.addAll(Arrays.asList(CanadianTerritory.values()));
        else
            regions.addAll(Arrays.asList(USState.values()));
        
        return regions;
    }

    // Does NOT throw the VerifyError
    private Region[] getRegions(){
        return country == Country.CA
                ? CanadianTerritory.values()
                : USState.values();
    }
        
    

Did you find the solution?

I filed a bug report back in 2017, but it was closed.

The only "solution" I've seen thus far is to specifically downcast to the interface type when returning the enum array, even though the compiler gives a redundancy warning. From the examples above, that would be:

    // Will NOT throw the VerifyError, but compiler warns of redundant casting
    private Region[] getRegions(){
        if(country == Country.CA)
            return (Region[]) CanadianTerritory.values();
        else
            return (Region[]) USState.values();
    }