Installing or Upgrading the Dune binary #1833
Description
I don't think this is correct, if Dune is installed, then dune pkg is available, whatever the project root is.
There is two different things: detecting that dune pkg is installed or not which is what we want to do here. And latter check if the project root does contain a dune pkg project (lock file).
Originally posted by @voodoos in #1791 (comment)
Dune.make currently returns None if dune is not installed, right? That's an important start! Additionally to that, we also need to check if the installed dune version supports package management, i.e. if the dune pkg and dune tools exec commands are available.
Originally posted by @pitag-ha in #1791 (comment)
We need to be able to know if the dune binary is available and we also need to be able to check that the dune binary available supports dune pkg and dune tools exec commands. If any of these is unavailable, we can suggest to install dune to the latest (if absent) or upgrade dune