How to fix "untracked content" in git status for submodule in Git

First, find out which files are causing the "untracked content" status:

cd path/to/submodule
git status

Or from the parent repository:

git diff --submodule

This will show you the specific files that Git considers untracked within the submodule.

If you want Git to ignore untracked files in this submodule (the most common solution), add the ignore = untracked option to your .gitmodules file:

git config -f .gitmodules submodule.<path>.ignore untracked

For example, if your submodule is at vendor/library:

git config -f .gitmodules submodule.vendor/library.ignore untracked

Or manually edit .gitmodules:

[submodule "vendor/library"]
    path = vendor/library
    url = https://github.com/example/library.git
    ignore = untracked

Then commit the change:

git add .gitmodules
git commit -m "Ignore untracked content in submodule"

If you want to ignore both untracked and modified content in submodules (only show commit differences), use ignore = dirty:

git config -f .gitmodules submodule.<path>.ignore dirty

Available ignore options:
- none (default): Show all changes (untracked, modified, commits)
- untracked: Hide untracked files, show modified files and commits
- dirty: Hide all working tree changes, only show commit differences
- all: Ignore all changes (the submodule is invisible to status/diff)

Note: Using dirty or all can hide important changes, so use with caution.

If the untracked files should be permanently ignored in the submodule, add them to the submodule's .gitignore:

cd path/to/submodule
echo "*.pyc" >> .gitignore
echo "__pycache__/" >> .gitignore
echo "node_modules/" >> .gitignore

If you don't want to modify the submodule's tracked .gitignore, you can use the local exclude file instead:

echo "*.log" >> .git/modules/path/to/submodule/info/exclude

The exclude file works like .gitignore but is not part of the repository.

If the untracked files are not needed and you want to remove them:

cd path/to/submodule
git clean -fd

To clean all submodules at once from the parent repository:

git submodule foreach git clean -fd

Warning: git clean -fd permanently deletes untracked files and directories. Use git clean -fdn first for a dry run to see what would be deleted.

If you want to completely reset submodules to match the parent repository's expectations:

git submodule update --force --recursive

This will checkout the exact commit recorded in the parent repository, discarding local changes.

To also clean untracked files:

git submodule foreach --recursive git clean -fd
git submodule update --force --recursive

If you just want to temporarily hide submodule changes without modifying configuration:

# Ignore only untracked content
git status --ignore-submodules=untracked

# Ignore all submodule changes
git status --ignore-submodules=dirty

# Same for git diff
git diff --ignore-submodules=dirty

You can set this as a default in your Git config:

git config --global diff.ignoreSubmodules dirty
git config --global status.submoduleSummary false