Reduce build time Xamarin.Android project

Question

Currently we encounter really long build times for our Android project.

Is this (see build log below) a normal build time for a Xamarin Android project with the following amount of assets?

• 350 drawables
• 210 Layout files
• 65 values xml files

Do you have any suggestion to speed-up the build time? This is really annoying.

PS. we also have the problem that we need to do a clean build every time we change something in a xml file (for example when changing a color in a layout file).

Here is the build log when I do a clean DEBUG build for an Android emulator:

Done building project "MyApp.Droid.csproj".

Project Evaluation Performance Summary:
139 ms /Users/stefan/Projects/myapp/Core/CoreApp.Core.csproj 2 calls

Project Performance Summary:
70 ms /Users/stefan/Projects/myapp/Core/CoreApp.Core.csproj 4 calls
166920 ms /Users/stefan/Projects/myapp/Droid/CoreApp.Droid.csproj 1 calls

Target Performance Summary:
* ms GetCopyToOutputDirectoryItems 1 calls
0 ms PrepareResourceNames 1 calls
0 ms BeforeResGen 1 calls
0 ms AfterBuild 1 calls
0 ms RunCodeAnalysis 1 calls
0 ms _XamarinBuildAddDownloadedItems 1 calls
0 ms _XamarinBuildDownload 1 calls
0 ms SetWin32ManifestProperties 1 calls
0 ms RunXamarinPackageAnalysis 1 calls
0 ms BeforeResolveReferences 1 calls
0 ms GenerateManifests 1 calls
0 ms RunXamarinProjectAnalysis 1 calls
0 ms UpdateAndroidResources 1 calls
0 ms _XamarinBuildDownloadMasterTarget 1 calls
0 ms PrepareProjectReferences 1 calls
0 ms ResolveNativeReferences 1 calls
0 ms CreateCustomManifestResourceNames 1 calls
0 ms ResolveReferences 1 calls
0 ms GetFrameworkPaths 1 calls
0 ms ResGen 1 calls
0 ms CoreBuild 1 calls
0 ms PrepareForRun 1 calls
0 ms BeforeBuild 1 calls
0 ms CreateSatelliteAssemblies 1 calls
0 ms AfterResolveReferences 1 calls
0 ms Compile 1 calls
0 ms _CopySourceItemsToOutputDirectory 1 calls
0 ms _LinkAssemblies 1 calls
0 ms PrepareResources 1 calls
0 ms AfterResGen 1 calls
0 ms _ResolveMonoAndroidFramework 1 calls
0 ms UpdateAndroidAssets 1 calls
0 ms BeforeCompile 1 calls
0 ms GetTargetFrameworkProperties 1 calls
0 ms AfterCompile 1 calls
0 ms _UpdateAndroidResources 1 calls
0 ms _SetupDesignTimeBuildForBuild 1 calls
0 ms BuildOnlySettings 1 calls
0 ms BclBuildSetRunningFullBuild 1 calls
0 ms _SetupDesignTimeBuildForIntellisense 1 calls
0 ms _XamarinAndroidSupportVectorDrawableArgs 1 calls
0 ms ResolveSDKReferences 1 calls
0 ms _IncludeInstanceRunReference 1 calls
0 ms _ValidateLinkMode 1 calls
0 ms _CheckTargetFramework 1 calls
0 ms _RoslynPublicSignHack 1 calls
0 ms Build 1 calls
0 ms _EmitXamarinProjectAnalysisResults 1 calls
0 ms _CheckForContent 1 calls
0 ms _EmitXamarinPackageAnalysisResults 1 calls
0 ms ComputeIntermediateSatelliteAssemblies 1 calls
0 ms ExpandSDKReferences 1 calls
0 ms ProcessGoogleServicesJsonChecks 1 calls
0 ms _SetupInstantRun 1 calls
0 ms _SetupApplicationJavaClass 1 calls
0 ms BclBuildGetTargetPath 1 calls
0 ms _SeparateAppExtensionReferences 1 calls
0 ms _SetupDesignTimeBuildForCompile 1 calls
0 ms GetTargetPath 2 calls
0 ms _ReadPropertiesCache 1 calls
0 ms GetInstalledSDKLocations 1 calls
0 ms _SetTargetFrameworkMonikerAttribute 1 calls
0 ms GetNativeManifest 1 calls
0 ms _GetReferenceAssemblyPaths 1 calls
0 ms _CheckForDeletedResourceFile 1 calls
0 ms BclBuildAddProjectReferenceProperties 1 calls
0 ms _CheckForCompileOutputs 1 calls
0 ms _AddMultiDexDependencyJars 1 calls
0 ms _DefineBuildTargetAbis 1 calls
0 ms _CheckInstantRunCondition 1 calls
0 ms _GenerateSatelliteAssemblyInputs 1 calls
0 ms _CheckProjectItems 1 calls
0 ms _ValidateResourceCache 1 calls
0 ms VectorDrawableCheckBuildToolsVersionTask 1 calls
0 ms _CalculateAdditionalResourceCacheDirectories 1 calls
0 ms _SetEmbeddedWin32ManifestProperties 1 calls
1 ms _CreateAdditionalResourceCache 5 calls
1 ms _XbdRestoreItems_supportv4 1 calls
1 ms _XbdRestoreItems_transition 1 calls
1 ms _XbdRestoreItems_supportcoreui 1 calls
1 ms _XbdRestoreItems_supportcompat 1 calls
1 ms _CreatePackageWorkspace 1 calls
1 ms _XbdRestoreItems_supportannotations 1 calls
1 ms _XbdRestoreItems_supportfragment 1 calls
1 ms _XbdRestoreItems_firebaseanalytics 1 calls
1 ms _XbdRestoreItems_firebaseiid 1 calls
1 ms _XbdRestoreItems_recyclerviewv7 1 calls
1 ms _XbdRestoreItems_firebasecommon 1 calls
1 ms _XbdRestoreItems_playservicesmaps 1 calls
1 ms _XbdRestoreItems_firebaseanalyticsimpl 1 calls
1 ms _XbdRestoreItems_supportvectordrawable 1 calls
1 ms _XbdRestoreItems_supportmediacompat 1 calls
1 ms _XbdRestoreItems_playservicesanalytics 1 calls
1 ms _XbdRestoreItems_playservicesbase 1 calls
1 ms _XbdRestoreItems_playservicestasks 1 calls
1 ms _XbdRestoreItems_playservicesads 1 calls
1 ms _XbdRestoreItems_playservicesgass 1 calls
1 ms _XbdRestoreItems_supportcoreutils 1 calls
1 ms _XbdRestoreItems_playservicesanalyticsimpl 1 calls
1 ms _XbdRestoreItems_playservicesadslite 1 calls
1 ms _XbdRestoreItems_playservicestagmanagerv4impl 1 calls
1 ms _XbdRestoreItems_customtabs 1 calls
1 ms _XbdRestoreItems_playservicesgcm 1 calls
1 ms _XbdRestoreItems_playservicesbasement 1 calls
1 ms _XbdRestoreItems_playservicesclearcut 1 calls
1 ms _XbdRestoreItems_design 1 calls
1 ms _XbdRestoreItems_playservicesiid 1 calls
1 ms _XbdRestoreItems_cardviewv7 1 calls
1 ms _XbdRestoreItems_appcompatv7 1 calls
1 ms GenerateTargetFrameworkMonikerAttribute 1 calls
1 ms _SplitProjectReferencesByFileExistence 2 calls
1 ms _GenerateCompileInputs 1 calls
1 ms _GetAdditionalResourcesFromAssemblies 1 calls
1 ms _GetMonoPlatformJarPath 1 calls
1 ms _CheckForInvalidConfigurationAndPlatform 1 calls
1 ms _StripEmbeddedLibraries 1 calls
1 ms _CompileDex 1 calls
1 ms CoreResGen 1 calls
1 ms AssignProjectConfiguration 1 calls
1 ms _GetLibraryImports 1 calls
1 ms GetTargetPathWithTargetPlatformMoniker 2 calls
1 ms _XbdRestoreItems_animatedvectordrawable 1 calls
2 ms CheckAbiAndMinSDK 1 calls
2 ms _ExtractLibraryProjectImports 1 calls
2 ms _GetAddOnPlatformLibraries 1 calls
2 ms CreateManifestResourceNames 1 calls
2 ms SplitResourcesByCulture 1 calls
2 ms _ComputeAndroidAssetsPaths 1 calls
2 ms _CheckDuplicateJavaLibraries 1 calls
4 ms _ValidateAndroidPackageProperties 1 calls
4 ms GetReferenceAssemblyPaths 1 calls
4 ms _CreatePropertiesCache 1 calls
4 ms BclBuildValidateNugetPackageReferences 1 calls
5 ms _CreateIntermediateAssembliesDir 1 calls
5 ms _AddDebugStaticResources 1 calls
6 ms PrepareForBuild 1 calls
9 ms _XamarinAndroidBuildResourceRestore 1 calls
10 ms AssignTargetPaths 2 calls
11 ms _ResolveMonoAndroidSdks 1 calls
12 ms _WriteResolvedAssemblies 1 calls
13 ms _PrepareAssemblies 1 calls
13 ms BclBuildDetermineReferencesToRedirect 1 calls
14 ms _CopyConfigFiles 1 calls
16 ms _ConvertPdbFiles 1 calls
16 ms _GeneratePackageManagerJava 1 calls
20 ms _AddStaticResources 1 calls
26 ms _CollectConfigFiles 1 calls
30 ms _GetPrimaryCpuAbi 1 calls
35 ms _CollectPdbFiles 1 calls
36 ms _XamarinAndroidBuildAarRestore 1 calls
37 ms _CollectMdbFiles 1 calls
39 ms _DetermineJavaLibrariesToCompile 1 calls
42 ms CopyFilesToOutputDirectory 1 calls
67 ms _CollectMonoAndroidOutputs 1 calls
69 ms _GenerateCompileDependencyCache 1 calls
81 ms ImplicitlyExpandDesignTimeFacades 1 calls
84 ms _GenerateAndroidAssetsDir 1 calls
87 ms FindReferenceAssembliesForReferences 1 calls
93 ms _GetProjectReferenceTargetFrameworkProperties 2 calls
103 ms _ComputeAndroidResourcePaths 1 calls
105 ms ResolveProjectReferences 1 calls
122 ms _BuildAdditionalResourcesCache 1 calls
128 ms _CheckTargetFrameworks 1 calls
148 ms _XamarinAndroidBuildAarProguardConfigs 1 calls
195 ms _BuildLibraryImportsCache 1 calls
204 ms _CopyMdbFiles 1 calls
218 ms _ResolveSatellitePaths 1 calls
236 ms _FindJavaStubFiles 1 calls
245 ms ResolveAssemblyReferences 1 calls
259 ms IncrementalClean 1 calls
265 ms _FindCompiledJavaFiles 1 calls
384 ms _CleanGetCurrentAndPriorFileWrites 1 calls
402 ms _AdjustJavacVersionArguments 1 calls
449 ms _SetLatestTargetFrameworkVersion 1 calls
616 ms _ResolveAssemblies 1 calls
2325 ms _CopyFilesMarkedCopyLocal 1 calls
3294 ms _CopyIntermediateAssemblies 1 calls
3582 ms CoreCompile 1 calls
3708 ms _LinkAssembliesNoShrink 1 calls
4267 ms _GenerateAndroidResourceDir 1 calls
5510 ms _ResolveLibraryProjectImports 1 calls
6131 ms _GenerateJavaDesignerForComponent 1 calls
15153 ms _CompileJava 1 calls
15530 ms _GenerateJavaStubs 1 calls
27014 ms _CreateBaseApk 1 calls
34145 ms _CompileToDalvikWithDx 1 calls
41166 ms _UpdateAndroidResgen 1 calls
(* = timing was not recorded because of reentrancy)

Task Performance Summary:
* ms MSBuild 4 calls
0 ms GetFrameworkPath 1 calls
0 ms CheckProjectItems 1 calls
0 ms GetAppSettingsDirectory 1 calls
0 ms CalculateAdditionalResourceCacheDirectories 1 calls
0 ms VectorDrawableCheckBuildToolsVersionTask 1 calls
0 ms ResolveNonMSBuildProjectOutput 1 calls
0 ms GetReferenceAssemblyPaths 2 calls
0 ms GetAndroidDefineConstants 1 calls
1 ms AssignCulture 1 calls
1 ms ReadAdditionalResourcesFromAssemblyCache 1 calls
1 ms GetExtraPackages 2 calls
1 ms ReadLinesFromFile 1 calls
1 ms CreateTemporaryDirectory 2 calls
1 ms GetMonoPlatformJar 1 calls
1 ms GetJavaPlatformJar 1 calls
1 ms AssignProjectConfiguration 1 calls
1 ms CreateCSharpManifestResourceName 1 calls
1 ms ReadImportedLibrariesCache 1 calls
1 ms XmlPeek 1 calls
1 ms GetAndroidPackageName 1 calls
2 ms ReadLibraryProjectImportsCache 1 calls
2 ms GetAddOnPlatformLibraries 1 calls
2 ms CheckDuplicateJavaLibraries 1 calls
2 ms MakeDir 6 calls
2 ms CollectLibraryAssets 1 calls
3 ms AssignTargetPath 10 calls
3 ms Message 17 calls
4 ms ValidatePackageReferences 1 calls
5 ms FindAppConfigFile 1 calls
6 ms RemoveDirFixed 2 calls
8 ms ConvertDebuggingFiles 1 calls
8 ms XamarinBuildAndroidResourceRestore 1 calls
9 ms CreateResgenManifest 1 calls
9 ms CreateAndroidResourceStamp 1 calls
11 ms ConvertToAbsolutePath 1 calls
12 ms CreateProperty 70 calls
13 ms CopyConfigFiles 1 calls
13 ms CollectPdbFiles 1 calls
15 ms GeneratePackageManagerJava 1 calls
16 ms CopyResource 4 calls
17 ms Delete 3 calls
18 ms Hash 1 calls
19 ms CopyGeneratedJavaResourceClasses 2 calls
20 ms GetFilesThatExist 2 calls
23 ms CopyIfChanged 1 calls
30 ms GetPrimaryCpuAbi 1 calls
36 ms XamarinBuildAndroidAarRestore 1 calls
38 ms DetermineJavaLibrariesToCompile 1 calls
78 ms CopyMdbFiles 1 calls
81 ms WriteLinesToFile 6 calls
104 ms AndroidComputeResPaths 2 calls
121 ms GetAdditionalResourcesFromAssemblies 1 calls
128 ms CheckTargetFrameworks 1 calls
142 ms RemoveUnknownFiles 2 calls
146 ms XamarinBuildAndroidAarProguardConfigs 1 calls
195 ms GetImportedLibraries 1 calls
198 ms RemoveDuplicates 2 calls
212 ms FindUnderPath 5 calls
272 ms Touch 13 calls
402 ms AdjustJavacVersionArguments 1 calls
405 ms GenerateResourceDesigner 1 calls
448 ms ResolveSdks 1 calls
461 ms ResolveAssemblyReference 2 calls
595 ms ResolveAssemblies 1 calls
627 ms CreateItem 263 calls
3579 ms Csc 1 calls
3695 ms LinkAssemblies 1 calls
5509 ms ResolveLibraryProjectImports 1 calls
8166 ms GenerateJavaStubs 1 calls
9682 ms Copy 9 calls
15079 ms CreateMultiDexMainDexClassList 1 calls
15150 ms Javac 1 calls
19063 ms CompileToDalvik 1 calls
33129 ms Aapt 3 calls
48058 ms ConvertResourcesCases 3 calls
(* = timing was not recorded because of reentrancy)

Build succeeded.

Time Elapsed 00:02:46.92

The build configuration looks like:

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'MyApp-Debug|AndroidEmulator' ">
                <MonoAndroidResourcePrefix>Resources;Resources-MyApp</MonoAndroidResourcePrefix>
                <MonoAndroidAssetsPrefix>Assets;Assets-myapp</MonoAndroidAssetsPrefix>
                <AndroidResgenFile>Resources-MyApp\ResourceMyApp.designer.cs</AndroidResgenFile>
                    <AndroidExplicitCrunch>false</AndroidExplicitCrunch>
                <DebugSymbols>true</DebugSymbols>
                <DebugType>full</DebugType>
                <Optimize>false</Optimize>
                <OutputPath>bin\MyApp-Debug\AndroidEmulator</OutputPath>
                <DefineConstants>TRACE;MyApp;DEBUG</DefineConstants>
                <ErrorReport>prompt</ErrorReport>
                <WarningLevel>4</WarningLevel>
                <ConsolePause>false</ConsolePause>
                <EmbedAssembliesIntoApk>false</EmbedAssembliesIntoApk>
                <RunCodeAnalysis>true</RunCodeAnalysis>
                <AndroidEnableMultiDex>true</AndroidEnableMultiDex>
                <AndroidLinkMode>None</AndroidLinkMode>
                <AndroidUseSharedRuntime>true</AndroidUseSharedRuntime>
                <AndroidSupportedAbis>x86</AndroidSupportedAbis>
                <JavaMaximumHeapSize>2G</JavaMaximumHeapSize>
            </PropertyGroup>

Answer 1

Currently we encounter really long build times for our Android project.

This is fairly normal for a Xamarin.Android application that includes Xamarin.Forms and all of the respective support libraries. As you can see in your Performance Summary, we are seeing roughly 33s for resource parsing(aapt), 15s for java compilation (javac) and about 19s for dex compilation.

If you want to dig into this further, you can use a Diagnostic Build Output and manually invoke these commands on the command line and see how long they take each. Majority of this is work being done by the Android SDK build tooling which is somewhat a bottleneck.

There are also some great tips in the following Android Studio documentation that can be applied to Xamarin.Android projects as well:

https://developer.android.com/studio/build/optimize-your-build.html

we also have the problem that we need to do a clean build every time we change something in a xml file (for example when changing a color in a layout file) ---> "ConvertResourcesCases" task failed unexpectedly

Here are some suggestion to solve this issue:

• Make sure you have full permissions of the folder that you place your project.
  • If you are using Mac, make sure your file is "unblock" under the file property.
  • If you are using Windows, right click on your folder, select Properties, select Security and give `Full Control as permission.
• Make sure there is no any non-English character in the root folder path.

Do you have any suggestion to speed-up the build time?

Enabled Fast Deployment in the project settings.

You could enable new Fast Deployment feature in .csproj by adding this:

<AndroidFastDeploymentType>Assemblies:Dexes</AndroidFastDeploymentType>

This process speeds up the build/deploy/debug cycle because if only assemblies are changed, the package is not reinstalled. Please note that:

It works only when when the $(EmbedAssembliesIntoApk) MSBuild property is False, you could find it here.

The more detailed information about speed-up the build time you could find here:

Tips and tricks on how to speed up the time it takes to compile a Xamarin app.

Answer 2

Is this (see build log below) a normal build time for a Xamarin Android project with the following amount of assets?

Yes, it is. Even though in Native Android, it also need much time to build with so much assets.

Do you have any suggestion to speed-up the build time?

Yes, you can refer to this to optimize your build.

do a clean build every time we change something in a xml file

Try save the file and wait for a few seconds.