problem with ant script properties - ant

Question

The following is my ant script:
<project name="nightly_build" default="main" basedir="C:\Work\6.70_Extensions\NightlyBuild">
<target name="init">
<sequential>
<exec executable="C:/Work/Searchlatestversion.exe">
<arg line='"/SASE Lab Tools" "6.70_Extensions/6.70.102/ANT_SASE_RELEASE_"'/>
</exec>
<property file="C:/Work/latestbuild.properties"/>
<sleep seconds="10"/>
<echo message="The product version is ${Product_Version}"/>
<exec executable="C:/Work/checksnapshot.exe">
<arg line='"ANT_SASE_RELEASE_${Product_Version}_SASE Lab Tools-NightlyBuild" ANT_SASE_RELEASE_${Product_Version}_AnalyzerCommon-NightlyBuild ${Product_Version}-AppsMerge' />
</exec>
<property file="C:/Work/checksnapshot.properties"/>
<tstamp>
<format property="suffix" pattern="ddMMyyyyHHmm"/>
</tstamp>
</sequential>
</target>
<target name="main" depends="init">
<echo message="loading properties files.." />
<sleep seconds="10"/>
<echo message="Backing up folder" />
<move file="C:\NightlyBuild\NightlyBuild" tofile="C:\NightlyBuild\NightlyBuild.${suffix}" failonerror="false" />
<parallel>
<exec executable="C:/Work/sortfolder.exe">
<arg line="6" />
</exec>
<exec executable="C:/Work/6.70_Extensions/NightlyBuild/antc.bat">
</exec>
</parallel>
</target>
</project>
Basically the sequence goes something like this:
I will run Searchlatestversion.exe and write latestbuild.properties
Using the latestbuild.properties i will obtain ${Product_Version} and would like to allow checksnapshot.exe access to latestbuild.properties and obtain ${Product_Version}
checksnapshot.exe will then generate checksnapshot.properties which will then be used by the target in main antc.bat
am i doing something wrong over here? seems like ${Product_Version} is not being received well by checksnapshot.exe

Answer 1

You appear to have a hard coded wait period of 10 seconds for Searchlatestversion to write out your file. If the executable does not complete inside that time, ${Product_Version} cannot be read from file.
Have you considered using the Waitfor Ant Task? As the name implies, this will wait for a certain condition before it will allow the rest of the task to progress. You could do something like
<property name="props.file" value="C:/Work/latestbuild.properties"/>
<waitfor maxwait="10" maxwaitunit="second">
<available file="${props.file}"/>
</waitfor>
<property file="${props.file}"/>

Answer 2

Does Searchlatestversion.exe produce the file C:/Work/latestbuild.properties?
If so, should you not sleep/wait before you load that properties file?
You have this:
<exec .../>
<property file="C:/Work/latestbuild.properties"/>
<sleep seconds="10"/>
Should you not have this:
<exec ... />
<sleep seconds="10"/>
<property file="C:/Work/latestbuild.properties"/>