Merge pull request #3211 from fsprojects/another-perf-fix

We never get this working correctly

src/Paket.Core/embedded/Paket.Restore.targets

@@ -60,6 +60,9 @@
       <Output TaskParameter="ConsoleOutput" PropertyName="PaketRestoreLockFileHash" />
     </Exec>
 
+    <!-- Debug whats going on -->
+    <Message Importance="low" Text="calling paket restore with targetframework=$(TargetFramework) targetframeworks=$(TargetFrameworks)" />
+
     <PropertyGroup Condition="Exists('$(PaketRestoreCacheFile)') ">
       <!-- if no hash has been done yet fall back to just reading in the files and comparing them -->
       <PaketRestoreCachedHash Condition=" '$(PaketRestoreCachedHash)' == '' ">$([System.IO.File]::ReadAllText('$(PaketRestoreCacheFile)'))</PaketRestoreCachedHash>
@@ -77,9 +80,11 @@
     <!-- Step 2 Detect project specific changes -->
     <ItemGroup>
       <MyTargetFrameworks Condition="'$(TargetFramework)' != '' " Include="$(TargetFramework)"></MyTargetFrameworks>
-      <MyTargetFrameworks Condition="'@(TargetFrameworks)' != '' " Include="$(TargetFrameworks)"></MyTargetFrameworks>
+      <!-- Don't include all frameworks when msbuild explicitly asks for a single one -->
+      <MyTargetFrameworks Condition="'$(TargetFrameworks)' != '' AND '$(TargetFramework)' == '' " Include="$(TargetFrameworks)"></MyTargetFrameworks>
       <PaketResolvedFilePaths Include="@(MyTargetFrameworks -> '$(MSBuildProjectDirectory)\obj\$(MSBuildProjectFile).%(Identity).paket.resolved')"></PaketResolvedFilePaths>
     </ItemGroup>
+    <Message Importance="low" Text="MyTargetFrameworks=@(MyTargetFrameworks) PaketResolvedFilePaths=@(PaketResolvedFilePaths)" />
     <PropertyGroup>
       <PaketReferencesCachedFilePath>$(MSBuildProjectDirectory)\obj\$(MSBuildProjectFile).paket.references.cached</PaketReferencesCachedFilePath>
       <!-- MyProject.fsproj.paket.references has the highest precedence -->
@@ -89,7 +94,6 @@
       <!-- paket.references -->
       <PaketOriginalReferencesFilePath Condition=" !Exists('$(PaketOriginalReferencesFilePath)')">$(MSBuildProjectDirectory)\paket.references</PaketOriginalReferencesFilePath>
 
-      <PaketResolvedFilePath>$(MSBuildProjectDirectory)\obj\$(MSBuildProjectFile).$(TargetFramework).paket.resolved</PaketResolvedFilePath>
       <DoAllResolvedFilesExist>false</DoAllResolvedFilesExist>
       <DoAllResolvedFilesExist Condition="Exists(%(PaketResolvedFilePaths.Identity))">true</DoAllResolvedFilesExist>
       <PaketRestoreRequired>true</PaketRestoreRequired>
@@ -112,7 +116,7 @@
     <!-- Step 2 b detect relevant changes in project file (new targetframework) -->
     <PropertyGroup Condition=" '$(DoAllResolvedFilesExist)' != 'true' ">
       <PaketRestoreRequired>true</PaketRestoreRequired>
-      <PaketRestoreRequiredReason>target-framework '$(TargetFramework)' or '$(TargetFrameworks)'</PaketRestoreRequiredReason>
+      <PaketRestoreRequiredReason>target-framework '$(TargetFramework)' or '$(TargetFrameworks)' files @(PaketResolvedFilePaths)</PaketRestoreRequiredReason>
     </PropertyGroup>
 
     <!-- Step 3 Restore project specific stuff if required -->