How to Fix: Copying an SSH ID to a server from a certain computer yields an error while the same command works fine from other computers

The error message 'Pseudo-terminal will not be allocated because stdin is not a terminal' and 'ssh: Could not resolve hostname umask 077; test -d ~/.ssh || mkdir ~/.ssh ; cat >> ~/.ssh/authorized_keys && (test -x /sbin/restorec: Name or service not known)' occurs when attempting to copy an SSH key to a remote server using the `ssh-copy-id` command. This issue affects users who are trying to automate the process of transferring their SSH keys from a local computer to a remote server.

This error can be frustrating, especially for system administrators and developers who rely on automation tools like `ssh-copy-id`. Fortunately, there are steps that can be taken to resolve this issue.

⚠️ Common Causes

• The primary reason for this error is related to the way the `ssh-copy-id` command handles pseudo-terminals. When the command is run without a pseudo-terminal, it cannot allocate one, which leads to the 'Pseudo-terminal will not be allocated because stdin is not a terminal' error message.
• Another possible cause of this issue is related to the hostname resolution problem. The `ssh-copy-id` command attempts to resolve the hostname of the remote server using the 'umask 077' method, but if this fails, it can result in the 'Could not resolve hostname umask 077' error message.

🔧 Proven Troubleshooting Steps

🎯 Final Words

By enabling pseudo-terminal mode and resolving hostname resolution issues, you should be able to successfully copy your SSH key to the remote server using the `ssh-copy-id` command. Remember to test the command on other computers to ensure that the issue is resolved.