升级AGP至8.0后Release构建Retrofit泛型类型异常求助

迁移至Android Studio Flamingo并将AGP版本升级至8.0后，使用Retrofit调用API时仅在Release构建中出现如下异常，Debug构建可正常运行：

java.lang.IllegalArgumentException: Response must include generic type (e.g., Response)

API调用代码 #

fun getIpApiData() = viewModelScope.launch {
    ipApiLiveData.postValue(Resource.Loading())
    try {
        if (AppUtility.hasInternetConnection()) {
            AppUtility.showProdLog("INSIDE IP API")
            val response = repository.getIpApiJson(AppConstants.IP_API_FIELDS)
            ipApiLiveData.postValue(handleIpApiResponse(response))
            AppUtility.showProdLog("IP API SUCCESS")
        } else {
            ipApiLiveData.postValue(Resource.Error(app.getString(R.string.internet_connection), AppConstants.ERROR_CODES.APP_ERROR_CODE))
        }
    } catch (e: Exception) {
        AppUtility.showProdLog("EXCEPTION IP API - $e")
        AppUtility.showProdLog("EXCEPTION IP API - ${e.message}")
        val errorMsg = handleException(e)
        ipApiLiveData.postValue(Resource.Error(errorMsg, AppConstants.ERROR_CODES.APP_ERROR_CODE))
    }
}

suspend fun getIpApiJson(fields: String) =
    RetrofitInstance.buildServiceWithURL(IGToolsAPI::class.java, IP_API_BASE_URL).getIpApiJson(fields)

@GET("json")
suspend fun getIpApiJson(@Query("fields") fields: String): Response<IpApiJson>

当前ProGuard配置 #

-keep class com.google.gson.reflect.TypeToken
-keep class * extends com.google.gson.reflect.TypeToken
-keep public class * implements java.lang.reflect.Type

# Retrofit does reflection on generic parameters. InnerClasses is required to use Signature and
# EnclosingMethod is required to use InnerClasses.
-keepattributes Signature, InnerClasses, EnclosingMethod

# Retrofit does reflection on method and parameter annotations.
-keepattributes RuntimeVisibleAnnotations, RuntimeVisibleParameterAnnotations

# Keep annotation default values (e.g., retrofit2.http.Field.encoded).
-keepattributes AnnotationDefault

# Retain service method parameters when optimizing.
-keepclassmembers,allowshrinking,allowobfuscation interface * {
    @retrofit2.http.* <methods>;
}

# Ignore annotation used for build tooling.
-dontwarn org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement

# Ignore JSR 305 annotations for embedding nullability information.
-dontwarn javax.annotation.**

# Guarded by a NoClassDefFoundError try/catch and only used when on the classpath.
-dontwarn kotlin.Unit

# Top-level functions that can only be used by Kotlin.
-dontwarn retrofit2.KotlinExtensions
-dontwarn retrofit2.KotlinExtensions$*

# With R8 full mode, it sees no subtypes of Retrofit interfaces since they are created with a Proxy
# and replaces all potential values with null. Explicitly keeping the interfaces prevents this.
-if interface * { @retrofit2.http.* <methods>; }
-keep,allowobfuscation interface <1>

# Keep inherited services.
-if interface * { @retrofit2.http.* <methods>; }
-keep,allowobfuscation interface * extends <1>

# With R8 full mode generic signatures are stripped for classes that are not
# kept. Suspend functions are wrapped in continuations where the type argument
# is used.
-keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation

# R8 full mode strips generic signatures from return types if not kept.
-if interface * { @retrofit2.http.* public *** *(...); }
-keep,allowoptimization,allowshrinking,allowobfuscation class <3>

该问题源于AGP 8.0默认启用的R8全模式过度剥离了泛型签名，导致Retrofit无法识别Response<IpApiJson>的泛型参数，以下是针对性修复步骤：

1. 补充Retrofit泛型签名保留规则 #

在ProGuard规则中添加以下配置，精准匹配返回Response<*>的Retrofit接口方法，确保泛型信息不被剥离：

# 保留Retrofit服务方法的Response泛型签名
-if interface * { @retrofit2.http.* public retrofit2.Response<*> *(...); }
-keep,allowoptimization,allowshrinking,allowobfuscation class <3>

2. 显式保留数据模型类结构 #

确保IpApiJson模型类不被混淆，且其字段与泛型信息（如果有）完整保留，添加：

# 替换为IpApiJson实际所在包路径
-keep class com.your.package.IpApiJson { *; }
# 若模型类包含泛型字段，强制保留签名
-keepattributes Signature

3. 调整R8全模式配置（临时方案） #

若暂时无法适配全模式，可在gradle.properties中关闭全模式：

android.enableR8.fullMode=false

注：长期建议适配全模式，以获得更优的代码压缩效果。

4. 更新Retrofit版本（可选） #

确保使用适配AGP 8.0的Retrofit稳定版本（如2.9.0及以上），旧版本对R8全模式的兼容性较差。

内容的提问来源于stack exchange，提问作者Ankush Kapoor