Update a submodule to the latest commit

Question

I have a project A which is a library and it is used in a project B.

Both projects A and B have a separate repository on github BUT inside B we have a submodule of A.

I edited some classes on the library, which is in the repo A, I pushed on the remote repo, so the library (repo A) is updated.

These updates do not reflect on the "reference" (the submodule) the submodule refers to a previous commit.... what should I do in order to update the submodule on git?

First do: `git submodule update --remote --merge` to make sure the submodules point to the most recent hash (valid after git 1.8). Then commit the pointer to the new hash of your submodules by committing the submodules: `git add proj/submodule` then `git commit -m 'adding new submodule'` my favorite answer is this one: https://stackoverflow.com/a/42175412/1601580 — Charlie Parker, Apr 27 '21 at 17:46

Kjuly · Accepted Answer · 2019-10-23T05:51:19.597

550

Enter the submodule directory:

cd projB/projA

Pull the repo from you project A (will not update the git status of your parent, project B):

git pull origin master

Go back to the root directory & check update:

cd ..
git status

If the submodule updated before, it will show something like below:

# Not currently on any branch.
# Changed but not updated:
#   (use "git add ..." to update what will be committed)
#   (use "git checkout -- ..." to discard changes in working directory)
#
#       modified:   projB/projA (new commits)
#

Then, commit the update:

git add projB/projA
git commit -m "projA submodule updated"

UPDATE

As @paul pointed out, since git 1.8, we can use

git submodule update --remote --merge

to update the submodule to the latest remote commit. It'll be convenient in most cases.

edited Oct 23 '19 at 05:51

answered Nov 19 '11 at 02:26

Kjuly

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BTW, if you are not the owner of the submodule, you can just do `git submodule update` when someone else updated the projA(you'll get a new commit id). – Kjuly Nov 19 '11 at 03:09
i own the submodule main repo(proj A) but i am a committer in the proj B. – fat Nov 19 '11 at 10:19
@Kjuly After the commit, how does one push it to the remote? Is it just `git push` ? – KR29 Apr 08 '16 at 18:24
2

@KR29 right, and the full cmd is `git push `, e.g. `git push origin dev`. – Kjuly Apr 09 '16 at 02:31
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`git submodule update` only works without flags when a commit has been pulled (in proj B) that updates the refs to the submodule(s) in question (proj A). To update proj B to reference the `HEAD` of the remote tracking branch for proj A, you'll want to do `git submodule update --remote --merge` as shown in Paul Hatcher's answer below. – Ben Burns Oct 22 '19 at 20:42
I am not sure if I am doing something wrong. I did `git submodule update --remote --merge` I went to github but they git sub repos are still pointing to the wrong commit. How to I have github also point to the right commit? Also, how do I check that the local ones are pointing to the right commit? – Charlie Parker Apr 26 '21 at 19:26
you also have to do a `git add .` then a `git commit -m 'msg updating submodules'` I believe. – Charlie Parker Apr 26 '21 at 20:54
@CharlieParker yeah, it's correct if only the submodule updated. But if there're some other files modified, they all will be added, which is not suit for the submodule updating commit msg. That's why I wrote `git add projB/projA` explicitly. ;) – Kjuly Apr 27 '21 at 00:50
@Kjuly apologies for the second question. Is `git submodule update --remote --merge` suppose to do everything? like do I still need to cd to the submodules pull and commit? It seems that `git submodule update --remote --merge` does nothing for me. When I cd into the submodules it shows old commits. – Charlie Parker Apr 27 '21 at 15:20
@CharlieParker Generally yes, `git submodule update --remote --merge` will update the submodule to the latest remote commit (no need to cd to the submodules to pull again). But I'm not quite sure about this option, I still prefer using the cd way to make sure the updating result is what I want (I'll check the log history). u can leave ur question below @paul's answer, I think he'll have a better experience on this option. ;) – Kjuly Apr 28 '21 at 01:25
Hi @Kjuly ! Thanks for your kind help. I am having a strange issue where no matter what I do (either I cd to the dir and do the pull or do the git submodule update etc) I cannot update one of my submodules. To resolve this I thought of two things that would help me 1) how do I force the submodule to tell me the gitlink/hash it really is pointing to? I've tried cding then git status but that doesn't seem to help. 2) is there a way to force the submodule to pull from the most recent gitlink of the original repo? Thanks for your time and fun attitude :) – Charlie Parker Apr 28 '21 at 14:35
I think my issues were resolved after reading https://stackoverflow.com/questions/11358082/empty-git-submodule-folder-when-repo-cloned with `git submodule update --init`. To get the latest hashes `git submodule status` worked. That will give you the whole hash so just read the beginning when comparing the local submodudles with github submodule hashes. Thanks again! – Charlie Parker Apr 28 '21 at 15:20
@CharlieParker I'm glad u've figured it out. :) – Kjuly Apr 29 '21 at 01:22
3

Update only one submodule: `git submodule update --remote --merge ` – ko80 Sep 17 '21 at 16:52

score 191 · Answer 2 · edited Apr 27 '21 at 17:49

191

Since git 1.8 you can do

git submodule update --remote --merge

This will update the submodule to the latest remote commit. You will then need to add and commit the change so the gitlink in the parent repository is updated:

First, git add it

git add project/submodule_proj_name

then git commit it

git commit -m 'gitlink to submodule_proj_name was updated'

the git push it

git push

And then push the changes as without this, the SHA-1 identity the pointing to the submodule won't be updated and so the change won't be visible to anyone else.

edited Apr 27 '21 at 17:49

Charlie Parker

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answered Feb 11 '17 at 11:36

Paul Hatcher

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Even though I do `git commit` everyone else is still not seeing it. `On branch master` `Your branch is up-to-date with 'origin/master'.` `Changes not staged for commit:` `modified: SubmoduleA (new commits)` `modified: SubmoduleB (new commits)` – Max N Mar 12 '18 at 14:42
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Have you done a "git push" after your commit, bear in mind commit just changes your local repository, you have to push it out to the remote for everyone else to see it – Paul Hatcher Mar 13 '18 at 10:04
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Missing from this answer (but noted in other answers below): the updated submodule(s) need to be staged with `git add` before committing. – joshng May 30 '19 at 14:50
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@joshng I feel that everyone who is at the point where they are working on submodules would understand that. This is the only post that helped me out, thanks very much. – Husk Rekoms Jul 22 '19 at 16:11

score 49 · Answer 3 · edited Dec 21 '11 at 16:29

If you update a submodule and commit to it, you need to go to the containing, or higher level repo and add the change there.

git status

will show something like:

modified:
   some/path/to/your/submodule

The fact that the submodule is out of sync can also be seen with

git submodule

the output will show:

+afafaffa232452362634243523 some/path/to/your/submodule

The plus indicates that the your submodule is pointing ahead of where the top repo expects it to point to.

simply add this change:

git add some/path/to/your/submodule

and commit it:

git commit -m "referenced newer version of my submodule"

When you push up your changes, make sure you push up the change in the submodule first and then push the reference change in the outer repo. This way people that update will always be able to successfully run

git submodule update

More info on submodules can be found here http://progit.org/book/ch6-6.html.

If you don't see a `+` when you run `git submodule`, make sure you've initialized and imported the submodules. The commands for that are `git submodule init` and `git submodule update`, respectively. — fureigh, Mar 21 '17 at 17:26

score 22 · Answer 4 · answered Oct 20 '14 at 06:31

22

Single line version

git submodule foreach "(git checkout master; git pull; cd ..; git add '$path'; git commit -m 'Submodule Sync')"

answered Oct 20 '14 at 06:31

Andy Webov

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score 6 · Answer 5 · answered Nov 23 '20 at 11:15

6

None of the above answers worked for me.

This was the solution, from the parent directory run:

git submodule update --init;
cd submodule-directory;
git pull;
cd ..;
git add submodule-directory;

now you can git commit and git push

answered Nov 23 '20 at 11:15

Francesco Borzi

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Your answer was close compared with the previous, except for this: added submodule sometimes is not point to a branch, you dont need to add the submodule on each modification – JRichardsz May 19 '22 at 17:27

score 6 · Answer 6 · edited Oct 05 '22 at 23:22

Solution 1

To make it simple.

Ran this command to get the latest of the submodule:

git submodule update --remote --merge

or 

git submodule update --remote

now, we need to update the reference in our parent repo, that can be done using this command:

git add <<submodulesfoldername>>

note: <> == name of my sub module folder git add sub-modules (remember to commit and push with your code, the reference of the latest commit would have been added)

Solution 2

If the above solution doesn't pull the latest, Try This:

git submodule update --init --recursive

score 4 · Answer 7 · answered Apr 25 '19 at 21:30

A few of the other answers recommend merging/committing within the submodule's directory, which IMO can become a little messy.

Assuming the remote server is named origin and we want the master branch of the submodule(s), I tend to use:

git submodule foreach "git fetch && git reset --hard origin/master"

Note: This will perform a hard reset on each submodule -- if you don't want this, you can change --hard to --soft.

score 1 · Answer 8 · answered Jun 19 '16 at 01:02

My project should use the 'latest' for the submodule. On Mac OSX 10.11, git version 2.7.1, I did not need to go 'into' my submodule folder in order to collect its commits. I merely did a regular

git pull --rebase

at the top level, and it correctly updated my submodule.

score 0 · Answer 9 · answered Jul 04 '18 at 15:11

0

Andy's response worked for me by escaping $path:

git submodule foreach "(git checkout master; git pull; cd ..; git add \$path; git commit -m 'Submodule Sync')"

answered Jul 04 '18 at 15:11

Miguel Fernandes Muldy

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Likely the reason why [@Andy Webov's](https://stackoverflow.com/a/26459664/2632107) answer didn't require escaping was because they used single quotes around path, eg. `'$path'` – S0AndS0 Oct 25 '19 at 00:54

Update a submodule to the latest commit

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