We warn sometimes when we tell people to build from source and it's
not supported but we don't actually warn non-developers when invoking
the various install commands so: let's start doing so.
While we're here, also update the existing messaging to reflect the fact
we're on Mastodon now too and we don't want maintainers being
individually bothered about errors either.
I've tried to balance having messages here vs. having them be so long
at the beginning of installation that they will be missed or be overly
obnoxious.
- flip the messaging to refer to `HOMEBREW_NO_INSTALL_FROM_API` where relevant
- remove some duplicate checks
- better scope checks to just core tap formulae
- The `brew uninstall` command has `--zap`, so let's make `brew
reinstall` have parity here for a better user experience. (Requested
in issue 12983.)
- It feels weird that to get my new reinstall test to pass I had to add
`--zap` to `cask/cmd/install.rb`, not `cask/cmd/reinstall.rb` to get
the tests to pass. But the `brew reinstall --cask caffeine --zap`
command worked fine all the time. The CLI argument parser from the
test run was complaining about not knowing what `zap` was. As a
result, `--zap` now shows up as a switch in `brew install --help`
which I'm not 100% convinced is the desired UX. But I've edited the
description accordingly to specify that it will only work on
`reinstall` operations (and `--zap` on `install` is a no-op).
```
issyl0 at pictor in /opt/homebrew on reinstall-cask-zap
❯ brew reinstall --cask caffeine --zap
==> Downloading https://github.com/IntelliScape/caffeine/releases/download/1.1.3/Caffeine.dmg
Already downloaded: /Users/issyl0/Library/Caches/Homebrew/downloads/3d6ccfdd3b8d0ab37d1c2468d6e69078c2d31d3b12bf51947c4db21e5f376af2--Caffeine.dmg
==> Implied `brew uninstall --cask caffeine`
==> Backing App 'Caffeine.app' up to '/opt/homebrew/Caskroom/caffeine/1.1.3/Caffeine.app'
==> Removing App '/Applications/Caffeine.app'
==> Dispatching zap stanza
==> Trashing files:
~/Library/Application Support/com.intelliscapesolutions.caffeine
~/Library/Preferences/com.intelliscapesolutions.caffeine.plist
~/Library/Caches/com.intelliscapesolutions.caffeine
~/Library/HTTPStoages/com.intelliscapesolutions.caffeine.binarycookies
==> Removing all staged versions of Cask 'caffeine'
==> Installing Cask caffeine
==> Moving App 'Caffeine.app' to '/Applications/Caffeine.app'
🍺 caffeine was successfully installed!
```
There's a few bits of functionality that Homebrew has changed over the
years, makes sense as a sensible default but some people find really
annoying:
- automatically running `brew update`
- automatically running `brew cleanup`
- automatically upgrading outdated dependents
- automatically reinstalling broken dependents
For each of these: let's improve the documentation of the commands
whose behaviour is changed and the environment variables themselves.
