`autoremove` is destructive, and it can be difficult for users to
recover from it occuring when they weren't expecting it.
Fixes#17363FixesHomebrew/discussions#5395
This reverts commit 3d114161b3c3f1a95b94e8530f5bc45bb44bbbd9.
This reverts commit efb14a0ec264c4ef408dbbd5330905dd230e979c.
This suggests setting an environment variable that is different
than the one we end up checking so I've updated the warning so
now things match. If the goal was to have the name in the warning,
the environment variable checking logic could be updated. I have
no personal preference.
```console
$ brew irb
==> Interactive Homebrew Shell
Example commands available with: `brew irb --examples`
brew(main):001:0> ENV["HOMEBREW_NO_AUTO_REMOVE"] = "1"
=> "1"
brew(main):002:0> Homebrew::EnvConfig.no_autoremove?
=> false
brew(main):003:0> ENV["HOMEBREW_NO_AUTOREMOVE"] = "1"
=> "1"
brew(main):004:0> Homebrew::EnvConfig.no_autoremove?
=> true
```
Cleanup.rb:
- Added #autoremove method
- #autoremove is called in clean when HOMEBREW_AUTOREMOVE is set
Formula.rb:
- Added #unused_formulae_with_no_dependents and helpers
Removed old autoremove.rb module.
The refactor in 6e8f5d0958247e4b4d629866099ed2836a0e0863 means that the
exception no longer exposes the name of the package with multiple versions,
and as a result the rescuer is unable to print this information.
Because we now have a path in which MultipleVersionsInstalledError doesn't
have the name at all, we can't reasonably restore the old behaviour.
And since rack resolution happens purely internal to the function that
raises the exception, the caller has no way to know what name to use.
However, since the exception text gets printed anyway, we can just move
this text into the exception itself.
Fixes the following error:
```
Error: mpd has multiple installed versions
Error: undefined method `name' for #<MultipleVersionsInstalledError:0x00007fc6009d8870>
/usr/local/Homebrew/Library/Homebrew/cmd/uninstall.rb:137:in `rescue in uninstall'
/usr/local/Homebrew/Library/Homebrew/cmd/uninstall.rb:135:in `uninstall'
/usr/local/Homebrew/Library/Homebrew/brew.rb:119:in `<main>'
```
In #7526 a comparison for `paths` was introduced, but if `paths` is ever
`nil`, this triggers an error.
Coercing the variable to an Array should alleviate this problem, as
`nil.to_a` produces an empty and comparable Array.
Fixes#7540
Signed-off-by: Mike Fiedler <miketheman@gmail.com>
