title: Using git on a single server, i.e. no truly remote origin
body: <p>This seems so dumb, but I can't figure it out. Tons of instructions out there for cloning or adding a remote server, or pushing to a cloned repository. But I'm trying to figure out how to set up a git repository in a shared directory on a server, and let other people collaborate from clones in their personal directories.</p>
  
  <p>This is what I've tried:</p>
  
  <pre><code>abalter@U1:~$ mkdir mainrepo
  abalter@U1:~$ cd mainrepo/
  abalter@U1:~/mainrepo$ echo "inital entry" &gt; text.txt
  abalter@U1:~/mainrepo$ git init
  Initialized empty Git repository in /home/abalter/mainrepo/.git/
  abalter@U1:~/mainrepo$ git add text.txt 
  abalter@U1:~/mainrepo$ git commit -m "initial commit"
  [master (root-commit) fb829d6] initial commit
   1 file changed, 1 insertion(+)
   create mode 100644 text.txt
  abalter@U1:~/mainrepo$ cd ..
  abalter@U1:~$ git clone mainrepo/ userrepo
  Cloning into 'userrepo'...
  done.
  abalter@U1:~$ cd userrepo/
  abalter@U1:~/userrepo$ echo "users addition" &gt;&gt; text.txt 
  abalter@U1:~/userrepo$ git commit -am "users addition"
  [master 3d4ea94] users addition
   1 file changed, 1 insertion(+)
  abalter@U1:~/userrepo$ git add remote origin ../mainrepo/
  fatal: ../mainrepo/: '../mainrepo/' is outside repository
  abalter@U1:~/userrepo$ git push origin master
  Counting objects: 5, done.
  Writing objects: 100% (3/3), 267 bytes | 0 bytes/s, done.
  Total 3 (delta 0), reused 0 (delta 0)
  remote: error: refusing to update checked out branch: refs/heads/master
  remote: error: By default, updating the current branch in a non-bare repository
  remote: error: is denied, because it will make the index and work tree inconsistent
  remote: error: with what you pushed, and will require 'git reset --hard' to match
  remote: error: the work tree to HEAD.
  remote: error: 
  remote: error: You can set 'receive.denyCurrentBranch' configuration variable to
  remote: error: 'ignore' or 'warn' in the remote repository to allow pushing into
  remote: error: its current branch; however, this is not recommended unless you
  remote: error: arranged to update its work tree to match what you pushed in some
  remote: error: other way.
  remote: error: 
  remote: error: To squelch this message and still keep the default behaviour, set
  remote: error: 'receive.denyCurrentBranch' configuration variable to 'refuse'.
  To /home/abalter/mainrepo/
   ! [remote rejected] master -&gt; master (branch is currently checked out)
  error: failed to push some refs to '/home/abalter/mainrepo/'
  abalter@U1:~/userrepo$ 
  </code></pre>
  
  <p>I'm clearly missing a step, but I don't know what it is.</p>
  
  <p><strong>EDIT</strong>
  I realize it should have been <code>git remote add origin ../mainrepo</code>. But </p>
  
  <pre><code>abalter@U1:~/userrepo$ git remote add origin ../mainrepo
  fatal: remote origin already exists.
  abalter@U1:~/userrepo$ 
  </code></pre>
  
  <p>If it already exists, why can't I push to it?</p>