Git submodules still with detached head

Question

When I fetch my git project that uses submodules, the submodules have a detached head. I read many posts here on stackoverflow and they say that that problem should be solved - so I'm doing something wrong, but can't detect what.

That's what happens:

M.Grunwald % git clone -b BranchName ssh://git@10.128.28.106:7999/~m.grunwald/repo_with_submodules.git some_repo
Cloning into 'some_repo'...
remote: Counting objects: 26, done.
remote: Compressing objects: 100% (26/26), done.
remote: Total 26 (delta 9), reused 0 (delta 0)
Receiving objects: 100% (26/26), done.
Resolving deltas: 100% (9/9), done.
M.Grunwald % cd some_repo
M.Grunwald % cat .gitmodules


[submodule "Library/MyLib"]
        path = Library/MyLib
        url = ssh://git@10.128.28.106:7999/~m.grunwald/my_lib.git
        branch = BranchName


M.Grunwald % git submodule init
Submodule 'Library/MyLib' (ssh://git@10.128.28.106:7999/~m.grunwald/my_lib.git) registered for path 'Library/MyLib'
M.Grunwald % git submodule update --remote
Cloning into
'/cygdrive/c/Users/m.grunwald/Documents/TMP/some_repo/Library/MyLib'...
Submodule path 'Library/MyLib': checked out '5c665e00cca5eb24d9b615294807520a6036fa90'
git submodule update --remote  4.31s user 10.61s system 10% cpu 2:21.52 total
M.Grunwald % cd Library/MyLib
M.Grunwald % git status
HEAD detached at 5c665e0
nothing to commit, working tree clean

So, the .gitmodules contains the submodule, including "branch = branchname" and I call submodule update with --remote ... What is still missing?

% git --version git version 2.12.3

That's what happens if I switch to BranchName (cwd is some_repo/Library/MyLib):

M.Grunwald% git branch -r
  origin/HEAD -> origin/master
  origin/BranchName
M.Grunwald % git checkout BranchName
Branch BranchName set up to track remote branch BranchName from origin.
Switched to a new branch 'BranchName'
M.Grunwald % git status
On branch BranchName
Your branch is up-to-date with 'origin/BranchName'.
nothing to commit, working tree clean
M.Grunwald % cd ..
M.Grunwald % ..
M.Grunwald % git status
On branch BranchName
Your branch is up-to-date with 'origin/BranchName'.
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)
  (commit or discard the untracked or modified content in submodules)

        modified:   Library/MyLib (new commits)

M.Grunwald % git diff Library/MyLib
diff --git a/Library/MyLib b/Library/MyLib
index 1341b30..5c665e0 160000
--- a/Library/MyLib
+++ b/Library/MyLib
@@ -1 +1 @@
-Subproject commit 1341b30ae55df1afc7265a9110fbf09661dd627b
+Subproject commit 5c665e00cca5eb24d9b615294807520a6036fa90

And if you check out `BranchName` in your submodule, do you see a change in the superproject? — Nils Werner, May 17 '17 at 10:31
Possible duplicate of [Git submodules: Specify a branch/tag](http://stackoverflow.com/questions/1777854/git-submodules-specify-a-branch-tag) — kowsky, May 17 '17 at 11:58
The only problem with a detached head in a submodule is when you need to commit changes. Then you just need to remember to check out the appropriate branch before you commit those changes. — crashmstr, May 17 '17 at 12:10

score 0 · Answer 1 · edited May 23 '17 at 11:47

Looks normal to me. What exactly is your problem? A submodule is always in a detached head state, even if it is properly set up to track a branch (see link below). When you switch branches in your parent repository, you have to run git submodule update to update your submodules to the commit of the new branch, if it is different.

From this answer, which seems to adress exactly what you want to know:

Note that the result, for each updated submodule, will always be a detached HEAD, as Dan Cameron note in his answer.

Git submodules still with detached head

1 Answers1