I've recently initialized my MacBook Pro 10.2 restoring from a TimeMachine Backup. It installed macOS Catalina GM on a Beta (Not sure about that, but now I got version 19B77a (10.15.1).
After this installation, there are problems installing applications or updating etc.
After some investigation I've discovered that the system is unable to write the /tmp directory.
I've tried to made an ls to the / directory:
$ ls -lah /
total 9
drwxr-xr-x 22 root admin 704B Feb 12 22:16 .
drwxr-xr-x 22 root admin 704B Feb 12 22:16 ..
-rw-rw-r-- 1 root admin 0B Oct 8 07:20 .DS_Store
lrwxr-xr-x 1 root admin 36B Feb 12 22:14 .VolumeIcon.icns -> System/Volumes/Data/.VolumeIcon.icns
---------- 1 root admin 0B Oct 8 07:20 .file
drwx------ 7 root admin 224B Apr 3 19:46 .fseventsd
drwxr-xr-x 2 root wheel 64B Oct 8 07:20 .vol
drwxr-xr-x+ 144 root admin 4.5K Apr 3 08:02 Applications
drwxr-xr-x 64 root wheel 2.0K Mar 11 17:57 Library
drwxr-xr-x@ 8 root wheel 256B Oct 15 07:37 System
drwxr-xr-x 5 root admin 160B Feb 13 01:22 Users
drwxr-xr-x 4 root wheel 128B Apr 3 19:50 Volumes
drwxr-xr-x@ 38 root wheel 1.2K Oct 15 07:46 bin
drwxr-xr-x 2 root wheel 64B Aug 24 2019 cores
dr-xr-xr-x 3 root wheel 4.2K Apr 3 19:46 dev
lrwxr-xr-x@ 1 root admin 11B Feb 12 22:06 etc -> private/etc
lrwxr-xr-x 1 root wheel 25B Apr 3 19:50 home -> /System/Volumes/Data/home
drwxr-xr-x 6 root wheel 192B Feb 13 01:22 opt
drwxr-xr-x 6 root wheel 192B Feb 13 01:22 private
drwxr-xr-x@ 64 root wheel 2.0K Feb 12 22:14 sbin
lrwxr-xr-x@ 1 root admin 11B Feb 12 22:14 tmp -> private/tmp
drwxr-xr-x@ 11 root wheel 352B Feb 12 22:14 usr
lrwxr-xr-x@ 1 root admin 11B Feb 12 22:14 var -> private/var
So I can see there is an incorrect group in the alias /tmp directory, but correct in /private:
$ ls -lah /private/
total 0
drwxr-xr-x 6 root wheel 192B Feb 13 01:22 .
drwxr-xr-x 22 root admin 704B Feb 12 22:16 ..
drwxr-xr-x 126 root wheel 3.9K Mar 30 00:07 etc
drwxr-xr-x@ 2 root wheel 64B Feb 13 01:22 tftpboot
lrwxr-xr-x@ 1 root wheel 11B Jun 27 2018 tmp -> private/tmp
drwxr-xr-x 31 root wheel 992B Feb 13 08:08 var
So the next step is try to set the correct group on /tmp, but, since Catalina, the System partition is read-only:
$ sudo chown root:wheel /tmp
Password:
chown: /tmp: Read-only file system
Obliviously I've already disabled SIP:
$ /usr/bin/csrutil status
System Integrity Protection status: disabled.
So, whats next? Got any suggestion?
Best Answer
I see exactly the same group ownership on my Catalina system, so I suggest that this isn't the cause of whatever problems you have.
Perhaps ask another question detailing the problems with installing applications and writing to /tmp ?