"Could not store vehicle to file" errors in SVN install

I am trying to install the latest build from SVN and when I run _build/transport.core.php, I get loads of these errors:



Is there anything with the permissions I should be taking in to account? Seems everything is set to 755..

Thanks in advance

You should be running the build on a machine you have full control over IMO, and the /core/packages/ directory definitely needs to be writable by whatever user is executing the PHP process. I typically run this locally to build the core transport and then upload it to a server where I’ve checked out or exported the same revision, but PHP definitely needs to be able to write to the file system to build the transport package.