Contents of linuxcompat.pkginfo:

<Package>
<PkgName>Linux API/ABI Compatibility Layer</PkgName>
<PkgVersion>0</PkgVersion>
<PkgItem type="directory" pathstyle="UNIX">/usr/abicore/linux</PkgItem>
<PkgItem type="file" pathstyle="UNIX">/usr/abicore/linux/README</PkgInfo>
</Package>