diff --git a/.appveyor.yml b/.appveyor.yml
new file mode 100644
index 0000000000..5372b51e43
--- /dev/null
+++ b/.appveyor.yml
@@ -0,0 +1,21 @@
+init:
+  - git config --global core.autocrlf true
+branches:
+  only:
+    - master
+    - /^release\/.*/
+    - dev
+    - /^(.*\/)?ci-.*$/
+install:
+  # Set depth to 50 because the commit we need may not be at the tip of the branch configured in .gitmodules
+  - git submodule update --init --depth=50 --recursive
+build_script:
+  - ps: .\run.ps1 default-build /t:ComputeGraph
+clone_depth: 1
+environment:
+  global:
+    DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
+    DOTNET_CLI_TELEMETRY_OPTOUT: 1
+test: off
+deploy: off
+os: Visual Studio 2017
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000000..d83797a701
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,20 @@
+language: csharp
+sudo: false
+dist: trusty
+env:
+  global:
+    - DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
+    - DOTNET_CLI_TELEMETRY_OPTOUT: 1
+mono: none
+addons:
+  apt:
+    packages:
+      - libunwind8
+branches:
+  only:
+    - master
+    - /^release\/.*/
+    - dev
+    - /^(.*\/)?ci-.*$/
+script:
+  - ./build.sh -t:ComputeGraph
diff --git a/build/repo.targets b/build/repo.targets
index 05e40b4a16..d1477e8be7 100644
--- a/build/repo.targets
+++ b/build/repo.targets
@@ -154,6 +154,14 @@
      DependsOnTargets="_PrepareRepositories;GeneratePropsFiles;ComputeGraph;_BuildRepositories" />
 
   <Target Name="ComputeGraph" DependsOnTargets="ResolveRepoInfo;GeneratePropsFiles">
+    <ItemGroup>
+      <_UndeclaredPackageArtifact Include="%(ArtifactInfo.PackageId)" Condition="'%(ArtifactInfo.ArtifactType)' == 'NuGetPackage'" />
+      <_UndeclaredPackageArtifact Remove="@(PackageArtifact)" />
+    </ItemGroup>
+
+    <Error Text="Undeclared package artifacts. Add these to artifacts.props:%0A  - @(_UndeclaredPackageArtifact, '%0A  - ')"
+      Condition=" @(_UndeclaredPackageArtifact->Count()) != 0 " />
+
     <RepoTasks.AnalyzeBuildGraph
       Solutions="@(Solution)"
       Artifacts="@(ArtifactInfo)"
@@ -179,8 +187,17 @@
   </Target>
 
   <Target Name="VerifyPackageArtifactConfig">
+    <Error Text="Invalid configuration of %(PackageArtifact.Identity). PackageArtifact must have the 'Category' metadata."
+           Condition="'%(PackageArtifact.Category)' == '' " />
+
     <Error Text="Invalid configuration of %(PackageArtifact.Identity). Packages marked as Metapackage='true' must be Category='ship'."
            Condition="'%(PackageArtifact.Category)' != 'ship' AND '%(PackageArtifact.Metapackage)' == 'true' " />
+
+    <Error Text="Invalid configuration of %(PackageArtifact.Identity). Packages marked as LZMA='true' must be Category='ship'."
+           Condition="'%(PackageArtifact.Category)' != 'ship' AND '%(PackageArtifact.LZMA)' == 'true' " />
+
+    <Error Text="Invalid configuration of %(PackageArtifact.Identity). Packages marked as LZMATools='true' must be Category='ship'."
+           Condition="'%(PackageArtifact.Category)' != 'ship' AND '%(PackageArtifact.LZMATools)' == 'true' " />
   </Target>
 
   <Target Name="VerifyCoherentVersions" DependsOnTargets="ResolveRepoInfo">