When trying to create a build using propel-gen (propel v 1.4) I get:
[phing] Error reading project file [wrapped: Unable to open /path/to/project/build-propel.xml for reading: ]
I can't find a reference to this file in the propel documentation.
I realised that it was looking for files which are located in the propel/generator directory, but was using the current working directory as the base directory (I have propel-gen symlinked to /usr/bin so I can run it from anywhere).
The (kind of crappy) solution is just to cd into the propel/generator directory and run the build from there, so it uses that directory as the base path.