오늘chmod 오류

$ chmod 0777 BridgePoint.app/
chmod: Unable to change file mode on BridgePoint.app/: Read-only file system
$ chmod +w BridgePoint.app/
$

$ chmod +w  bridgepoint 
KM-S05:MacOS administrator$ ls -al
total 56
drwxrwxr-x@ 3 administrator  staff    102 10  8 10:19 .
drwxrwxr-x@ 6 administrator  staff    204  7 26 16:57 ..
-rwxr-xr-x@ 1 administrator  staff  27100  7 26 16:56 bridgepoint
$ sudo chmod 0777 bridgepoint 
Password:
chmod: Unable to change file mode on bridgepoint: Read-only file system
$ sudo chmod a+w bridgepoint 
chmod: Unable to change file mode on bridgepoint: Read-only file system