Xamarin.Android发布构建后Proguard无法生成mapping.txt求排查建议

Let's break down the common issues that could be stopping you from getting your mapping.txt file after running a ProGuard build, and how to fix them:

• Ensure ProGuard is actually executing during your build
  It's easy to assume ProGuard runs automatically, but that's not always the case. For example, debug build variants often skip ProGuard by default—make sure you're building a release variant. Check your build logs for mentions of "ProGuard"; if you don't see any, your build isn't triggering it. Double-check your build system settings (Gradle, Eclipse, etc.) to confirm ProGuard is enabled for your target variant.

• Verify the printmapping path is correct
  Your current config uses -printmapping mapping.txt, which writes the file to ProGuard's working directory (not your project root). By default, this is usually somewhere inside your build/ folder—like build/outputs/mapping/<your-variant>/ or build/intermediates/proguard/<your-variant>/.
  To make it easier to find, try specifying a path relative to your project root, e.g.:

  -printmapping ${projectDir}/mapping.txt
  

  (Note: ${projectDir} works for Gradle; adjust the variable if you're using a different build system.) Also, ensure your user account has write permissions for the target directory.

• Look for hidden errors masked by -ignorewarnings
  The -ignorewarnings flag suppresses most warning messages, but critical errors (like missing required classes) can still cause ProGuard to abort before generating the mapping file. Temporarily remove -ignorewarnings and rebuild—check the full log output for any error messages. Fix those issues first, then re-enable the flag if you still need it.

• Confirm your ProGuard config file is properly linked
  Setting the BuildAction to ProguardConfiguration might not be enough depending on your build system:

  • For Gradle projects: Make sure your build.gradle explicitly references your config file, like this (for Android):

    android {
        buildTypes {
            release {
                minifyEnabled true
                proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard.cfg'
            }
        }
    }
    

  • For Eclipse: Go to your project's properties > ProGuard, confirm your proguard.cfg is selected, and the "Run ProGuard" checkbox is ticked.

• Check if -dontobfuscate is interfering
  While -dontobfuscate disables obfuscation, ProGuard should still generate a mapping file for optimization/shrinking steps. However, some build systems might skip certain processes when obfuscation is off. Try temporarily commenting out -dontobfuscate and rebuilding to see if the mapping file appears.

内容的提问来源于stack exchange，提问作者Bogdan