add support for TRAMP about emacs-direnv

[wbolster]

i don't really see how that could work. this package patches the local env inside emacs, and inherently acts locally

[eush77]

I have just integrated Direnv with Tramp in my own configuration by prefixing commands executed in Tramp with direnv exec <default-directory>. I advised tramp-sh-handle-start-file-process instead of dealing with tramp-remote-process-environment, which goes quite contrary to how emacs-direnv operates and is less efficient, but it works.

[bricewge]

I think it need to patch the remote tramp environment instead of the local when in a tramp directory. Some example of changes are call-process should be replaced by process-file and process-environment by tramp-remote-process-environment.

Some days ago I ran into a package that added tramp support with a couple of line patch, unfortunately I can't manage to find it today. The only lead I have ATM is that page page of the TRAMP manual on how to integrate it with other packages.

EDIT: In emacs 27.1 executable-find can take an optional remote argument, see here.

[tshu-w]

@wbolster any update? There seems to be a pull request.