How do I revert my changes to a git submodule?

Question

I have a git submodule (RestKit) which I have added to my repo.

I accidentally changed some files in there and I'd like to go back to the source version. In order to do that, I tried to run

Mac:app-ios user$ git submodule update RestKit

But as you can see here, this did not work as it is still "modified content":

Mac:app-ios user$ git status
...
#   modified:   RestKit (modified content)

Even

Mac:app-ios user$ git submodule update -f RestKit 

doesn't revert locally modified files.
How do I reset the content of that submodule?

Answer 1

This works with our libraries running GIT v1.7.1, where we have a DEV package repo and LIVE package repo. The repositories themselves are nothing but a shell to package the assets for a project. all submodules.

The LIVE is never updated intentionally, however cache files or accidents can occur, leaving the repo dirty. New submodules added to the DEV must be initialized within LIVE as well.

Package Repository in DEV

Here we want to pull all upstream changes that we are not yet aware of, then we will update our package repository.

# Recursively reset to the last HEAD
git submodule foreach --recursive git reset --hard

# Recursively cleanup all files and directories
git submodule foreach --recursive git clean -fd

# Recursively pull the upstream master
git submodule foreach --recursive git pull origin master

# Add / Commit / Push all updates to the package repo
git add .
git commit -m "Updates submodules"
git push   

Package Repository in LIVE

Here we want to pull the changes that are committed to the DEV repository, but not unknown upstream changes.

# Pull changes
git pull

# Pull status (this is required for the submodule update to work)
git status

# Initialize / Update 
git submodule update --init --recursive

Answer 2

my way to reset all submodules (WITHOUT detaching & keeping their "master" branch):

git submodule foreach 'git checkout master && git reset --hard $sha1'

Answer 3

If you want to do this for all submodules, without having to change directories, you can perform

git submodule foreach git reset --hard

You can also use the recursive flag to apply to all submodules:

git submodule foreach --recursive git reset --hard

Answer 4

Move into the submodule's directory, then do a git reset --hard to reset all modified files to their last committed state. Be aware that this will discard all non-committed changes.

Answer 5

A more fail-safe method than all previous answers:

git submodule deinit -f .
git submodule update --init

The first command completely "unbinds" all submodules, the second then makes a fresh checkout of them.
It takes longer than the other methods, but will work whatever the state of your submodules.

Answer 6

This worked for me, including recursively into submodules (perhaps that's why your -f didn't work, cause you changed a submodule inside the submodule):

git submodule update -f --recursive