How to reproduce:
1. Create a new project
2. Change platform to Android
3. Edit Package Name and switch Scripting Backend to IL2CPP
4. Build Android Player
Result: Build fails and "Succeeded" message is present

Build fails with these errors:
Failed running /Applications/Unity 2018.3.0a6/Unity 2018.3.0a6.app/Contents/il2cpp/build/il2cppcore/il2cppcore.dll --convert-to-cpp --emit-null-checks --enable-array-bounds-check --dotnetprofile="unityaot" --compile-cpp --libil2cpp-static --platform="Android" --architecture="ARMv7" --configuration="Release" --outputpath="/Users/ieva/Downloads/Testil2cppAndroid/Temp/StagingArea/assets/bin/Data/Native/armeabi-v7a/libil2cpp.so" --cachedirectory="/Users/ieva/Downloads/Testil2cppAndroid/Assets/../Library/il2cpp_android_armeabi-v7a/il2cpp_cache" --additional-include-directories="/Applications/Unity 2018.3.0a6/PlaybackEngines/AndroidPlayer/Tools/bdwgc/include" --additional-include-directories="/Applications/Unity 2018.3.0a6/PlaybackEngines/AndroidPlayer/Tools/libil2cpp/include" --tool-chain-path="/Users/ieva/android-ndk-r16b" --map-file-parser="/Applications/Unity 2018.3.0a6/Unity 2018.3.0a6.app/Contents/Tools/MapFileParser/MapFileParser" --assembly="/Users/ieva/Downloads/Testil2cppAndroid/Temp/StagingArea/assets/bin/Data/Managed/Unity.Analytics.dll" --assembly="/Users/ieva/Downloads/Testil2cppAndroid/Temp/StagingArea/assets/bin/Data/Managed/UnityEngine.dll" --generatedcppdir="/Users/ieva/Downloads/Testil2cppAndroid/Temp/StagingArea/Il2Cpp/il2cppOutput"

and

Exception: /Applications/Unity 2018.3.0a6/Unity 2018.3.0a6.app/Contents/il2cpp/build/il2cppcore/il2cppcore.dll did not run properly!

And at the end Build succeeded message is present

Reproducible: 2018.3.0a6 (eadcddd25045)
Not reproducible: 2018.3.0a5 (20706b925e3c)