Permission denied to create a symbolic link; sudo errors out

Question

I am trying to install phalcon development tools. In the documentation they said:

Create a symbolic link to the phalcon.php script:

ln -s ~/phalcon-devtools/phalcon.php /usr/bin/phalcon
chmod ugo+x /usr/bin/phalcon

and after connecting to my Ubuntu server, at the step of creating symbolic link to the phalcon.php script I get an error:

ubuntu@ip-000-00-0-00:/$ sudo ln -s ~/phalcon-devtools/phalcon.php /usr/bin/phalcon
sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set

How can I complete the installation?

When I try without sudo I get:

ubuntu@ip-000-00-0-00:/$ ln -s ~/phalcon-devtools/phalcon.php /usr/bin/phalcon
ln: failed to create symbolic link ‘/usr/bin/phalcon’: Permission denied

Documentation which I followed

I have tried all the answers from this question but still getting same errors: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set

Solution

Seems like /usr/bin/sudo is broken as mentioned. You can try to fix it by booting your linux machine in recovery mode and fixing it by running the commands:

• Change owner back to root (uid 0) chown root:root /usr/bin/sudo
• Fix permissions ONLY IF THEY ARE INCORRECT. Run ls -l /usr/bin/sudo and permissions should be -rwsr-xr-x. If they are not, fix them by running chmod 4755 /usr/bin/sudo.

If all goes well then you should have sudo back!

Comments

[Mr world wide]

i have tried all the answers but still im getting the same errors.

[Zanna]

seems like you've broken sudo - or do you only get this error when you try to make this particular symbolic link? Could you tell us about your environment?

[vidarlo]

Can you provide the output of ls -l /usr/bin/sudo? It looks like sudo's permissions are messed up. The sudo binary needs the setuid bit, and has to be owned by root.