os/exec does not invoke the system shell and does not have PATH env variable
Kaniko command is not being interpreted by a shell, which is why PATH, as well as the rest of ENV variables are not present when running Kaniko with the wrapper.
From the exec package documentation:
...the os/exec package intentionally does not invoke the system shell and does not expand any glob patterns or handle other expansions, pipelines, or redirections typically done by shells.
Edited by Daniel Juarez