How to run a task before updating source files?

I need to run a task in CruiseControl .NET before checking for modification in source control. I mean this task should be the very first thing that CruiseControl will always do. I see <prebuild&g开发者_运维问答t; section in cc.config, but it is for running tasks before building a solution, so it is not exactly what I need.

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Prebuild DOES fire before the source control get. It comes after the source control block but still fires first. Here's an example I've been using:

<cb:define subversionpath="c:\Program Files\Subversion\bin\svn.exe"
/>

 <cb:define name="svn50">
<executable>$(subversionpath)</executable>
<workingDirectory>D:\Projects\B50\Source</workingDirectory>
<trunkUrl>svn://machineName/branches/B_50/Source</trunkUrl>
<autoGetSource>true</autoGetSource>
</cb:define>

 <project name="StreamlineCheckBuild" queue="B50">
<triggers>
  <intervalTrigger seconds="180" />
</triggers>
<sourcecontrol type="svn">
  <cb:svn50/>
  <deleteObstructions>true</deleteObstructions>
  <forceUpdate>true</forceUpdate>
</sourcecontrol>
<prebuild>
  <exec>
    <executable>$(subversionpath)</executable>
    <buildArgs>cleanup</buildArgs>
    <baseDirectory>D:\Projects\B50</baseDirectory>
  </exec>
</prebuild>
<tasks>
...
</tasks>
</cruisecontrol>

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Use batch file as proxy for the version control utility, eg. svn.bat:

echo do stuff
"c:\program files\Subversion\svn.exe" %*

Use executable atrribute to point to the bach file.