The problem is related to the resource forks of the file that has been compressed. In OS X, the resource forks are saved under a hidden file called
<filename>/rsrc, but when zipping the file, OS X silently stores the resource forks inside the zip under a folder named "__MACOSX". The problem is that you can't recover the resource forks in other operating systems, nor you can do it in OS X 10.3 or earlier using the regular "unzip" command line tool (10.4 or later do support resource forks in unzip). What we recommend you to do is either to:
Do not zip the original file. InstallBuilder will take care of the resource forks, populating them in OS X in a transparent way. Also, as you know InstallBuilder has ZIP compression, so you gain very little by already having the file zip-compressed.
If you still want to preserve the file zipped, when you decompress the file in the
<postInstallationActionList>, do it through a "open" command instead of an "unzip" command, like the following:
The open command will re-populate the resource forks so they will be again available as
/rsrc. Be careful though that the "open" command returns control immediately after invocation, so you would need to place a (wait five seconds) action after the mentioned (of course you can customize the wait interval to a safe value, in case you have a big file that takes time to uncompress). That way the uncompressed file will be fully available after the wait.
Note as well that we have set the
<workingDirectory> element, so the .zip file will be uncompressed in the same folder where it resides.
See also the related Mac OS X resource forks article
14 Sep '11, 06:01