MacOS – How to get Homebrew working under Mavericks

I had been doing most of my POSIX development on something other than my Mac after upgrading from Mountain Lion to Mavericks, and when I came back, Homebrew was not functioning at a smoke-test level. All calls seemed to get an allergic reaction to characters used to identify if a file was a tar.gz:

bash-3.2# brew install git
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require': /usr/local/Library/Homebrew/extend/pathname.rb:262: invalid multibyte escape: /^\037\213/ (SyntaxError)
invalid multibyte escape: /^\037\235/
invalid multibyte escape: /^\xFD7zXZ\x00/
    from     /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
    from /usr/local/Library/Homebrew/global.rb:1:in `<top (required)>'
    from     /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
    from     /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
    from /usr/local/bin/brew:10:in `<main>'

I searched for the error and turned up someone asking a similar question on copyquery.com; I reinstalled the OS X command line tools and then attempted to do a clean reinstall of Homebrew. That failed too:

...
==> Downloading and installing Homebrew...
remote: Counting objects: 162348, done.
remote: Compressing objects: 100% (45938/45938), done.
remote: Total 162348 (delta 115308), reused 162338 (delta 115300)
Receiving objects: 100% (162348/162348), 30.36 MiB | 3.31 MiB/s, done.
Resolving deltas: 100% (115308/115308), done.
From https://github.com/Homebrew/homebrew
 * [new branch]      master     -> origin/master
error: unable to unlink old 'Library/Homebrew/test/mach/a.out' (Permission denied)
error: git checkout-index: unable to create file Library/Homebrew/test/mach/fat.bundle (Permission denied)
error: unable to unlink old 'Library/Homebrew/test/mach/fat.dylib' (Permission denied)
error: git checkout-index: unable to create file Library/Homebrew/test/mach/i386.bundle (Permission denied)
error: unable to unlink old 'Library/Homebrew/test/mach/i386.dylib' (Permission denied)
error: git checkout-index: unable to create file Library/Homebrew/test/mach/x86_64.bundle (Permission denied)
error: unable to unlink old 'Library/Homebrew/test/mach/x86_64.dylib' (Permission denied)
Checking out files: 100% (3131/3131), done.
fatal: Could not reset index file to revision 'origin/master'.
Failed during: git reset --hard origin/master

And Homebrew doesn't want to be installed as root; it will bail if ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)" is installed as root.

I asked one time before if things were as bad as I thought after the MacPorts project systematically bit off more than it could chew and had breakage (like Gentoo, but you can usually search for error messages and find a Gentoo community solution within hours of something breaking–not so with what MacPorts was chewing!). I was told that the only reason it wasn't worse was that MacPorts etc. were available and provided a better alternative.

Right now I have a Mac running OS X 10.9 Mavericks, command line tools installed, and VMware Fusion with several clean Linux virtual machines available. If I want to do Unixy hacking (get the AngularJS tutorial working, and then tinker and hack a game into place), what are my live options for a development environment worth serious consideration? I'll be sad if I can't use Mac OS X as a hacker's Unix, but if the critical path to developer sanity includes something that doesn't run under Mavericks, I'm willing to swallow the irony and work with a Linux environment.

This may risk being a subjective questions, but given Mavericks plus any Linux I want, what are my serious options for tinkering with a software project?

Thanks,

—

When I ran "brew doctor", I got:

Warning: An outdated version of Git was detected in your PATH.
Git 1.7.10 or newer is required to perform checkouts over HTTPS from GitHub.
Please upgrade: brew upgrade git

  ^C

Inner Sanctum ~ $ brew upgrade git
Warning: It appears you have MacPorts or Fink installed.
Software installed with other package managers causes known problems for
Homebrew. If a formula fails to build, uninstall MacPorts/Fink and try again.
Error: git not installed

Would it help to install Git via a native installer?

–EDIT–

I've tried to uninstall Homebrew completely per instructions and reinstall, but it errors out:

Inner Sanctum ~ $ rm -rf /usr/local/Cellar /usr/local/.git && brew cleanup

Inner Sanctum ~ $ sudo /usr/local/bin/uninstall-homebrew.sh 
brew update first!

Inner Sanctum ~ $ ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
==> This script will install:
/usr/local/bin/brew
/usr/local/Library/...
/usr/local/share/man/man1/brew.1

Press RETURN to continue or any other key to abort
==> /usr/bin/sudo /bin/chmod g+rwx /Library/Caches/Homebrew
==> Downloading and installing Homebrew...
remote: Counting objects: 162492, done.
remote: Compressing objects: 100% (45968/45968), done.
remote: Total 162492 (delta 115424), reused 162478 (delta 115414)
Receiving objects: 100% (162492/162492), 30.32 MiB | 736.00 KiB/s, done.
Resolving deltas: 100% (115424/115424), done.
From https://github.com/Homebrew/homebrew
 * [new branch]      master     -> origin/master
error: unable to unlink old 'Library/Homebrew/test/mach/a.out' (Permission denied)
error: unable to create file Library/Homebrew/test/mach/fat.bundle (Permission denied)
error: unable to unlink old 'Library/Homebrew/test/mach/fat.dylib' (Permission denied)
error: unable to create file Library/Homebrew/test/mach/i386.bundle (Permission denied)
error: unable to unlink old 'Library/Homebrew/test/mach/i386.dylib' (Permission denied)
error: unable to create file Library/Homebrew/test/mach/x86_64.bundle (Permission denied)
error: unable to unlink old 'Library/Homebrew/test/mach/x86_64.dylib' (Permission denied)
Checking out files: 100% (3132/3132), done.
fatal: Could not reset index file to revision 'origin/master'.
Failed during: git reset --hard origin/master

I've tried a couple of variants, and for everything but one run I've tried the attempt to install brew results in errors like the permission denied error above. I've presently done find / -name Homebrew, and deleted everything, and run the curl etc. command from /, in case it will work better for Library to be in fact /Library. Now it worked. I'm not sure which change worked. Which change made it work?