问题
My team has a large solution (~500 csproj's). We use VS2012, and build using TFS Build, which uses MSBuild 4. Currently we build serially, but we want to build in parallel (using msbuild /maxcpucount:4
). However, when I try it on my 4-proc machine, I get a weird failure:
11:2>CSC : fatal error CS0042: Unexpected error creating debug information file 'C:\Common\obj\Debug\Common.PDB' -- 'C:\Common\obj\Debug\Common.pdb: The process cannot access the file because it is being used by another process. [C:\Common\Common.csproj]
Looking at the log, 2 msbuild nodes were trying to build that same csproj, and thus colliding on writing some output:
10>Project "C:\Utils\Utils.csproj" (10) is building "C:\Common\Common.csproj" (11) on node 4 (default targets).
46:2>Project "C:\Objects\Objects.csproj" (46:2) is building "C:\Common\Common.csproj" (11:2) on node 1 (default targets).
Why would MSBuild try to build the same project twice?
回答1:
Cause: Someone was calling <MSBuild Projects="Common.csproj" Properties="..." />
. Then, MSBuild thinks that it should build Common.csproj again with those different properties, and it happened to occur at the same time with the regular compilation of Common.csproj.
Fix: Call <MSBuild ... />
without those unneeded properties.
Test:
Common.targets
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<Target Name="Build">
<Message Importance="high" Text="Build in $(MSBuildThisFile)" />
</Target>
<Target Name="After" DependsOnTargets="Build">
<Message Importance="high" Text="After in $(MSBuildThisFile)" />
</Target>
</Project>
Other.targets
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<Target Name="Build">
<Message Importance="high" Text="Build in $(MSBuildThisFile)" />
<MSBuild Projects="common.targets" Targets="Build" /> <!-- regular builds -->
<MSBuild Projects="common.targets" <!-- custom invocation with properties -->
Targets="After"
Properties="myprop=myvalue"
/>
</Target>
</Project>
Run:
> msbuild other.targets /clp:verbosity=minimal
Build in other.targets
Build in common.targets
Build in common.targets <<<< Common.targets Build is invoked again
After in common.targets
And indeed, removing Properties="myprop=myvalue"
solves the issue.
来源:https://stackoverflow.com/questions/17399862/msbuild-m4-fails-because-it-builds-the-same-project-twice