Determine number of git revisions with inline MSBuild task

build.xml

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

  <UsingTask TaskName="GitVersion" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll" >
    <ParameterGroup>
      <LocalPath ParameterType="System.String" />
      <Path ParameterType="System.String" />
      <CommitCount ParameterType="System.Int32" Output="true" />
    </ParameterGroup>
    <Task>
      <!--<Reference Include="" />-->
      <Using Namespace="System"/>
      <Using Namespace="System.Diagnostics"/>
      <Code Type="Fragment" Language="cs">
        <![CDATA[
          LocalPath = LocalPath ?? ".";
          Path = Path ?? "master";
          
          Log.LogMessage(MessageImportance.Low, "LocalPath is {0}", LocalPath);
          Log.LogMessage(MessageImportance.Low, "Path is {0}", Path);
          
          var psi = new ProcessStartInfo("cmd", "/c git rev-list " + Path + " --count") {
              UseShellExecute = false, 
              ErrorDialog = false, 
              CreateNoWindow = false, 
              WorkingDirectory = LocalPath,
              RedirectStandardOutput = true,
              RedirectStandardError = true
          };

          string result;
          using (var p = Process.Start(psi)) {
            p.WaitForExit();
            if (p.ExitCode != 0) {
              using (var standardError = p.StandardError) {
                Log.LogError(standardError.ReadToEnd());
              }
              return false;
            }

            using (var standardOutput = p.StandardOutput) {
              CommitCount = Int32.Parse(standardOutput.ReadToEnd());
            }
          }
]]>
      </Code>
    </Task>
  </UsingTask>

  <Target Name="demo">
    <GitVersion Path="master">
      <Output PropertyName="GitCommitCount" TaskParameter="CommitCount" />
    </GitVersion>

    <Message Text="Commit count: $(GitCommitCount)"/>
  </Target>
</Project>