Before this change, external commands, whether official or not, cannot
use the `env:` DSL for `Homebrew::CLI::Parser` without adding their
environment variable to `Homebrew::EnvConfig`.
Instead, if the method is not defined, check the environment variable
directly. This allows `env:` to be used as expected and allows
simplifying some (new) code in e.g. `brew bundle`.
- For the command `brew install --cask racket`, a user was reporting the
behaviour where despite `--cask` in the command, they were getting
output about the `racket` formula having been renamed:
```
$ brew install --cask racket
Warning: Use minimal-racket instead of deprecated racket
==> Downloading https://mirror.racket-lang.org/installers/8.7/racket-8.7-x86_64-macosx-cs.
==> Installing Cask racket
[...]
racket was successfully installed!
```
- The "instead of deprecated ..." messaging comes from the `TapLoader`
class `formula_name_path` method, so _something_ must be assuming
that everything is initially a formula before _later_ learning from
further args parsing that there's a `--cask` qualifier to scope to
only casks.
- There are always `@formula_options` and args parsing is recursive,
going through each option, so we check that the original `argv` items
include a `--cask` and skip calling the `formulae` method if that's
the case.
- After this change, the "formula renames" words no longer show up.
```
$ brew install --cask racket
==> Downloading https://mirror.racket-lang.org/installers/8.7/racket-8.7-aarch64-macosx-cs.dmg
==> Installing Cask racket
[...]
racket was successfully installed!
```
This ability was removed around a month
ago but needs to be added back in.
Developers want to be able to use the
`bump` and `audit` commands when on Linux.
This is especially useful for CI.
1. Validate options before constraint violations. This allows
us to error out when --cask is passed on Linux before getting
a constraint violation when --cask and --formula are set.
2. Skip printing the help page when --cask is passed on Linux.
- There's already a method on `CLI::Parser`, we don't need to hand-roll
the "number of dashes" detection.
Co-authored-by: Rylan Polster <rslpolster@gmail.com>
