fatal: 'origin' does not appear to be a git repository

I've a repository moodle on my Github account which I forked from the official repository.

I then cloned it on my local machine. It worked fine. I created several branches (under the master branch). I made several commits and it worked fine.

I don't know how I'm getting the following error when I do : git push origin master

fatal: 'origin' does not appear to be a git repository
fatal: The remote end hung up unexpectedly

How do I resolve the error without effecting my repository on Github?

I'm using Ubuntu 12.10

The contents of my .git/config after doing cat $(git rev-parse --show-toplevel)/.git/config gives:

[core]
    repositoryformatversion = 0
    filemode = true
    bare = false
    logallrefupdates = true
[branch "master"]
[branch "MOODLE_23_STABLE"]
[branch "MOODLE_24_STABLE"]
[remote "upstream"]
    url = git://git.moodle.org/moodle.git
    fetch = +refs/heads/*:refs/remotes/upstream/*

Solution

$HOME/.gitconfig is your global config for git.
There are three levels of config files.

 cat $(git rev-parse --show-toplevel)/.git/config

(mentioned by bereal) is your local config, local to the repo you have cloned.

you can also type from within your repo:

git remote -v

And see if there is any remote named 'origin' listed in it.

If not, if that remote (which is created by default when cloning a repo) is missing, you can add it again:

git remote add origin url/to/your/fork

The OP mentions:

Doing git remote -v gives:

upstream git://git.moodle.org/moodle.git (fetch) 
upstream git://git.moodle.org/moodle.git (push)

So 'origin' is missing: the reference to your fork.
See "What is the difference between origin and upstream in github"

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