* Move Homebrew to the top, common case for new devs
* Note that `brew install rbenv` includes ruby-build by default
* Be clear that `rbenv init` instructions are needed for shell setup
* Be explicit about starting a new shell to pick up PATH/init changes
* Use rbenv-doctor to conclusively demonstrate correct setup
* Separate upgrade instructions for Homebrew vs Git installs
Related: https://github.com/rbenv/ruby-build/pull/1106
I work on a team that has followed the Homebrew installations. More than once we've missed the `rbenv init` instruction and it has caused headaches down the road. This formatting makes it harder to miss.
The setenv function in fish shell has changed dramatically in
75600b6b53
It now conforms to the csh version, which takes at most two arguments.
In this init script, the form
setenv PATH prepend_something $PATH
had been used, which had too many arguments.
Since setenv isn't a native command in fish, a suitable replacement is
to use the "set -gx" command, which can consume multiple arguments.
This allows subcommand style plugins to properly autocomplete.
Existing commands are not affected.
Example, say you have support for `rbenv foo bar --flag`, then
this allows the last `--flag` argument to be properly completed.
Keeping rbenv-controlled variables to RBENV_* "namespace" helps with
discoverability (and tools like rbenv-env) but also consistency and a
very minor degree of safety/isolation from env impact.
This ensures that OLD_RBENV_VERSION is never exported. This makes the
implementation a little bit more complex, since more logic needs to be
pushed down into eval'd code.
The literal tilde in a PATH entry (e.g. `~/.rbenv/shims`) doesn't seem
to be supported by system `which` utility, but *does* seem to be
supported by `command -v` (used in `rbenv-which`) and `type -p`.
Therefore, we must strip away `~/.rbenv/shims` from PATH when looking up
executables for system Ruby, lest we risk infinite loop. We do so by
substituting any occurence of `~` in PATH with the value of `HOME`.
Per [the fish documentation for "source"](file:///usr/local/Cellar/fish/2.2.0/share/doc/fish/commands.html#source) - ". (a single period) is an alias for the source command. The use of . is deprecated in favour of source, and . will be removed in a future version of fish."
