github.com/hashicorp/packer@v1.14.3/website/content/partials/path/separator-note.mdx (about)

     1  Separate paths with a forward slash (`/`), especially when using relative paths in your configuration. 
     2  Windows uses backward slashes (`\`) to separate paths, but Packer only recognizes `/` as path
     3  separators when it creates builds from any non-Windows system. Packer also treat backslashes as plain text, which could lead to errors.