jackrusher

;; make sure you've set your default project with:
;; gcloud config set project <project-name>

(require 'tramp)
(add-to-list 'tramp-methods
  '("gcssh"
    (tramp-login-program        "gcloud compute ssh")
    (tramp-login-args           (("%h")))
    (tramp-async-args           (("-q")))
    (tramp-remote-shell         "/bin/sh")

hadley

Registering handlers

The key C function that powers both tryCatch() and withCallingHandlers() is do_addCondHands(). It creates handler object with mkHandlerEntry() then stores in the handler stack for the current frame. (More precisely it writes to R_HandlerStack, a global variable that is an alias to c->handlerstack)

The five R arguments to do_addCondHands() are classes, handlers, parentenv, target, and calling. These are combined with a result object (a list of length 4, returned by the exiting handler to doTryCatch()) to create the handler objects which have five components:

• The class, accessed with ENTRY_CLASS(e). A string given a class name; the handler will match all conditions that contain this component in their class vector.