1. In this case, we usually make patches that apply against the official source package and submit them to the original author. I noticed the malloc.h bug too, and submitted the patch to wcd's author, so it should be fixed in the next release: https://sourceforge.net/p/wcd/code/722/

In the meanwhile, we can add a patch to fix the issue. See our documentation about applying patches within a formula here: https://github.com/mxcl/homebrew/wiki/Formula-Cookbook#patches

3. Yes, you can! You can do that by defining a `caveats` method after the install method, like this:

```ruby
def caveats; <<--EOS.undent
  Some helpful text goes here.

  This text can be multiple lines.
EOS
end
```

That returns a string which will be printed after the installation succeeds.