When launching Preview.app on the command line, I get an 'Operation not permitted' error returned. % /System/Applications/Preview.app/Contents/MacOS/Preview /Volumes/myfs/Through_the_pines.jpg 2024-06-17 14:23:16.826 Preview[2745:37915] PVImageContainer initWithURL:file:///Volumes/myfs/Through_the_pines.jpg failed, error = Error Domain=NSCocoaErrorDomain Code=257 "The file “Through_the_pines.jpg” couldn’t be opened because you don’t have permission to view it." UserInfo={NSFilePath=/Volumes/myfs/Through_the_pines.jpg, NSUnderlyingError=0x6000022302a0 {Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"}} File permissions allow reading for all users: % ls -l /Volumes/myfs/Through_the_pines.jpg -rw-rw-r--@ 1 developer staff 2396454 Mar 25 10:48 /Volumes/myfs/Through_the_pines.jpg Am I right in assuming it's sandbox related?

Thanks for replying. I've run stat(1) asynchronously to verify that two processes querying the same file residing on my filesystem get the identical inode value. See below. % stat -f 'inode: %i' t.txt&; stat -f 'inode: %i' t.txt& [1] 1978 [2] 1979 inode: 1954135111 [2] + done stat -f 'inode: %i' t.txt inode: 1954135111 [1] + done stat -f 'inode: %i' t.txt What are the system expectations of a filesystem that my implementation should meet? Is it some struct vfs_attr value that should be set? It has to be something specific, shouldn't it? Is there anything else you could recommend in terms of troubleshooting this? Thanks.