This is just a file permissions problem. Our update system needs to copy two executable files (PixInsightUpdater and updater2) to a folder outside the PixInsight.app application bundle. For some reason (of the '
to protect you' kind) some of the latest Mac machines have been configured in a very restrictive way that prevents this copy, even on the user's home folder. This can be solved by just fixing access permissions. A good solution is creating a new user with administrative rights, simply because the default file access permissions applied to newly created user profiles are correct.
The next version of PixInsight, on which I am working hard since January, won't have this problem because the executable files won't be copied on OS X. However, incorrect file access permissions will always cause problems on all platforms, not just on OS X. On Linux and Windows these problems don't happen because system security mechanisms are simple, well defined and work very well (
UAC and elevated execution privileges on Windows;
setuid and setgid flags on FreeBSD and Linux). On OS X these things are fuzzy, and simple tasks such as copying a file to a different folder from an application become problematic.
