A quickie on demystifying part of how git works.

(No, it's not useful.)

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+# Git Is Not Magic
+
+I'm bored. Let's make a git repository out of whole cloth.
+
+Git repos are stored in .git:
+
+    fakegit$ mkdir .git
+
+They have a "symbolic ref" (which are text files, see [`man
+git-symbolic-ref`](http://jk.gs/git-symbolic-ref.html)) named `HEAD``,
+pointing to the currently checked-out branch. Let's use `master`. Branches are
+refs under `refs/heads` (see [`man
+git-branch`](http://jk.gs/git-branch.html)):
+
+    fakegit ((unknown))$ echo 'ref: refs/heads/master' > .git/HEAD
+
+The have an object database and a refs database, both of which are simple
+directories (see [`man
+gitrepository-layout`](http://jk.gs/gitrepository-layout.html) and [`man
+gitrevisions`](http://jk.gs/gitrevisions.html)). Let's also enable the reflog,
+because it's a great safety net if you use history-editing tools in git:
+
+    fakegit ((ref: re...))$ mkdir .git/refs .git/objects .git/logs
+    fakegit (master #)$
+
+Now `__git_ps1`, at least, is convinced that we have a working git repository.
+Does it work?
+
+    fakegit (master #)$ echo 'Hello, world!' > hello.txt
+    fakegit (master #)$ git add hello.txt
+    fakegit (master #)$ git commit -m 'Initial commit'
+    [master (root-commit) 975307b] Initial commit
+    1 file changed, 1 insertion(+)
+    create mode 100644 hello.txt
+    
+    fakegit (master)$ git log
+    commit 975307ba0485bff92e295e3379a952aff013c688
+    Author: Owen Jacobson <owen.jacobson@grimoire.ca>
+    Date:   Wed Feb 6 10:07:07 2013 -0500
+    
+        Initial commit
+
+[Eeyup](https://www.youtube.com/watch?v=3VwVpaWUu30).
+
+-----
+
+Should you do this? **Of course not.** Anywhere you could run these commands,
+you could instead run `git init` or `git clone`, which set up a number of
+other structures, including `.git/config` and any unusual permissions options.
+The key part here is that a directory's identity as "a git repository" is
+entirely a function of its contents, not of having been blessed into being by
+`git` itself.
+
+You can infer a lot from this: for example, you can infer that it's "safe" to
+move git repositories around using FS tools, or to back them up with the same
+tools, for example. This is not as obvious to everyone as you might hope; people