Error: sudo: sorry, you must have a tty to run sudo (Packer)

Error: sudo: sorry, you must have a tty to run sudo (Packer provisioner)

TL;DR

The remote sudo requires a TTY and Packer's SSH session does not allocate one. Set ssh_pty to true in the builder configuration.

The error

sudo: sorry, you must have a tty to run sudo

(often surfacing as Build 'amazon-ebs' errored: Error installing Chef: Install script exited with non-zero exit status 1 or a shell provisioner failure)

Fix it

1. Add "ssh_pty": true to the builder block (JSON) or ssh_pty = true (HCL).

   • Success check: the setting is present in the builder, not the provisioner.

2. Re-run packer build.

   • Success check: sudo commands in provisioners execute instead of failing.

3. If you control the image, the alternative is removing requiretty from sudoers, but ssh_pty is the portable fix.

   • Success check: either path eliminates the error.

When to use this

You hit this when provisioner scripts calling sudo fail on AMIs whose sudoers has requiretty (notably Amazon Linux and RHEL-family images).

When NOT to use this

Do not use this for password prompts from sudo (sudo: no tty present is different; provide ssh_password or NOPASSWD) or for non-sudo script failures.

Compatibility

Packer 1.x, SSH communicator, sudo with requiretty.

Variants

• Error installing Chef: Install script exited with non-zero exit status 1 with the tty message buried in the log
• Shell provisioner scripts failing only on their sudo lines

Root cause

Some distributions ship sudoers with Defaults requiretty. Packer's SSH sessions run without a pseudo-terminal by default, so sudo refuses to run at all.

Edge cases

• ssh_pty can change output buffering slightly; if a script parses interactive output, test it.
• WinRM/Windows builders do not use this setting; it is SSH-only.