What this error means
The completion feature selects an operation through the environment variable associated with bin. For example, ship uses _SHIP_COMPLETE. Supported values are:
bash_sourceandbash_complete.elvish_sourceandelvish_complete.zsh_sourceandzsh_complete.fish_sourceandfish_complete.nushell_sourceandnushell_complete.powershell_sourceandpowershell_complete.
The received value is stored in details.mode. It normally comes from a hand-written shell profile, an outdated adapter, or a caller that set the completion environment variable itself.
How to fix it
Generate and install the current adapter again by following Shell completion, and remove old environment-variable assignments from the profile. Ordinary CLI invocations should not persistently set the completion variable.