How can I convert a ‘normal’ Git repository to a bare one?
The main difference seems to be:
in the normal Git repository, you have a .git folder inside the repository containing all relevant data and all other files making up your working copy
in a bare Git repository, there is no working copy and the folder (let’s call it repo.git) contains the actual repository data
In short: replace the contents of repo with the contents of repo/.git, then tell the repository that it is now a bare repository.
To do this, execute the following commands:
cd repo
mv .git ../repo.git # renaming just for clarity
cd ..
rm -fr repo
cd repo.git
git config --bool core.bare true
Note that this is different from doing a git clone --bare to a new location (see below).