OSX big-sur-base update removed sudo permissions / coredumps now inaccessible

[anarazel]

@fkorotkov Unfortunately it seems the update in #37 removed the rights to sudo. We used sudo to change the permissions of /cores so we can get corefiles for crashes during CI. Unfortunately without changing the permissions on /cores, no core files are logged :(

ls -ld /cores/ || true
drwxr-xr-x  2 root  wheel  64 Jan  1  2020 /cores/
id || true
uid=501(admin) gid=20(staff) groups=20(staff),12(everyone),61(localaccounts),79(_appserverusr),80(admin),81(_appserveradm),98(_lpadmin),264(_webdeveloper),701(com.apple.sharepoint.group.1),33(_appstore),100(_lpoperator),204(_developer),250(_analyticsusers),395(com.apple.access_ftp),398(com.apple.access_screensharing),399(com.apple.access_ssh),400(com.apple.access_remote_ae)
ulimit -c unlimited
sudo chmod 777 /cores || true
sudo: a terminal is required to read the password; either use the -S option to read from standard input or configure an askpass helper
sudo: a password is required
sudo -n id || true
sudo: a password is required

And indeed, without that no core files are created:

sleep 5 & kill -SEGV $! || true
sleep 5
/var/folders/tn/f_9sf1xx5t14qm_6f83q3b840000gn/T/scripts6694d2c422acd208a0072939487f6999.sh: line 10:  3132 Segmentation fault: 11  sleep 5
ls -l /cores/ || true

[fkorotkov]

Oh. Maybe the OS upgrade reset the sudoers. Sudo password inside the VM is admin so as a workaround you use it.

[anarazel]

Ah, yes, that works. Should others encounter this, I added this to our .cirrus.yml:

  # An update to the cirrus OSX image removed passwordless sudo. Try to allow
  # it again. The existing sudoers uses env_reset without secure_path,
  # which means that 'sudo su' fails because 'su' isn't on PATH anymore.
  # https://github.com/cirruslabs/osx-images/issues/38
  fix_sudo_script:
    - echo admin | sudo -S /bin/bash -c 'echo "admin ALL=(ALL:ALL) NOPASSWD: ALL"|tee /etc/sudoers.d/admin'
    - echo 'Defaults        secure_path="/bin:/usr/bin:/usr/ucb:/usr/local/bin"'|sudo /usr/bin/tee /etc/sudoers.d/path

[fkorotkov]

This should be fixed now.