Le forum de XCAS

The installer xcas.pkg on xcas_osx4 installed /usr/local/bin/xcas with owner 501 and group 501 ... but I was not logged in as 501 at the time. Fortunately, xcas runs OK since others are allowed to read and execute the file. It looks like most applications in /usr/local/bin/ are assigned owner root and group admin.

I have indeed an umask of 022, hence no access problem for other users. It seems to be a problem only if the user with ID 501 removes or modifies files in /usr/local, which seems fortunately very unlikely if he is not an Unix fan inside a Terminal.