"brew install berkeley-db4" appears to be working again. simplified instructions by removing the berkeley-db4 workaround.
Github-Pull: #6286
Rebased-From: a3a80c253cdd0299f92b9e1ba9888f0f9421f245
After exiting, you'll get a warning that the install is keg-only, which means it wasn't symlinked to `/usr/local`. You don't need it to link it to build bitcoin, but if you want to, here's how:
$ brew link --force berkeley-db4
### Building `bitcoind`
1. Clone the github tree to get the source code and go into the directory.