Scenario:
You made a git repo on workstation 1, committed your changes, then from workstation 2 made a git init/pull. More changes, more commit… and its time to push all that mess back to workstation 1 ( the original )

$git push workstation1.tld

Counting objects: 32, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (22/22), done.
Writing objects: 100% (24/24), 13.63 KiB, done.
Total 24 (delta 6), 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 rocket.x.TLD.com:~/code/pydbgp
 ! [remote rejected] master -> master (branch is currently checked out)
error: failed to push some refs to 'rocket.x.lijit.com:~/code/pydbgp'

What the hell?

Stack overflow to the rescue with this Answer at stackoverflow

So basically… on workstation 1 do

Workstation1$git branch BeforeThePushBranch
Workstation1$git checkout BeforeThePushBranch
Workstation2$git push workstation1
Workstation1$git checkout master

Bam, back working again