Homebrew to date has been a refreshing change to MacPorts; a lot less time consuming and a lot less problematic than previous experiences of using MacPorts.
When fixing up a Rails application to use wicked_pdf, a PDF generation Gem i started having some problems with wkhtmltopdf, the binary that generates the PDF's. A quick Google showed that there appears to be one or two issues with the 0.11.rc1 version and recommendation to downgrade to a previous version: 0.9.9.
This wasn't a process i'd had to go through before with Homebrew so i thought i'd document what worked as it's not as clear cut and intuitive as the rest of the Homebrew commands.
OS X instructions:
about 10 months ago