Possible issue with outdated formulae about homebrew-rmtree

[beeftornado]

Interesting. I'll definitely take a look. Seems like it could be tricky to find the root cause though. Thanks for the report!

[beeftornado]

I believe the issue is as you stated, with outdated dependencies. It seems as though when, in your example, lua is outdated, rmtree is not considering it installed and then gets excluded from subsequent operations. Should be pretty straightforward to fix.

[beeftornado]

And it looks like I have my very own test case. On my computer, brew uses node only prints out yarn. But when I try and fake remove yarn,

$ brew rmtree --dry-run yarn
This is a dry-run, nothing will be deleted
==> Examining installed formulae required by yarn...
 /

Can safely be removed
----------------------
yarn

Won't be removed
-----------------


Order of operations
-------------------
yarn
Would have removed yarn

It should have also removed node. Both node and yarn are outdated.

[beeftornado]

Ah, ok. Specifically the issue is with how we get the formula instance of what you want to remove. In my case, I have yarn 1.5, but rmtree is using the formula for yarn 1.6, which depends on node latest, which I don't have installed, which is why it isn't getting removed.

$ brew info yarn
yarn: stable 1.6.0
JavaScript package manager
https://yarnpkg.com/
Conflicts with:
  hadoop (because both install `yarn` binaries)
/usr/local/Cellar/yarn/1.5.1_1 (14 files, 4.1MB) *
  Built from source on 2018-03-20 at 15:53:57
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/yarn.rb
==> Dependencies
Recommended: node ✘
==> Options
--without-node
        Build without node support

[beeftornado]

Ok, I think I found a solution. Now when I try and remove yarn, it correctly looks at installed dependencies.

$ brew rmtree --dry-run yarn
This is a dry-run, nothing will be deleted
==> Examining installed formulae required by yarn...
 /

Can safely be removed
----------------------
yarn
node

Won't be removed
-----------------
icu4c is used by harfbuzz, sqlite

Order of operations
-------------------
yarn
node
Would have removed yarn
Would have removed node

I'll publish the fix for this shortly. Thanks again for finding this and including all that helpful info @airdrummingfool