Remove ISymbianSDK#getPrefixFile. You can get this from ISDKBuildInfo#getPrefixFromVariantCfg().
<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
<name>com.nokia.carbide.search.system-feature</name>
<comment></comment>
<projects>
</projects>
<buildSpec>
</buildSpec>
<natures>
</natures>
</projectDescription>