What You Need To Know About The New Git 1.8.3
blogs.atlassian.com
blogs.atlassian.com
Homebrew backed out 1.8.3 because of this.
Edit: Specifically, I've got ".* .un~" and ".*.sw?" in my global excludes file, but they're showing up as untracked (not ignored) when my repo's .gitignore has some !-type patterns. Perhaps something about the precedence of such rules was changed.