Editing Troubleshooting of GIT (section)

=== Git Shows Files as Modified After chmod — File Mode Changes ===

'''Problem'''

After running <code>chmod +x</code> or copying the repository between different operating systems or file systems, Git may report files as modified even though their contents have not changed:

<pre>
git status

modified: scripts/deploy.sh
</pre>

Running <code>git diff</code> may show only a file mode change:

<pre>
diff --git a/scripts/deploy.sh b/scripts/deploy.sh
old mode 100644
new mode 100755
</pre>

In Git file modes:

* <code>100644</code> means a regular non-executable file.
* <code>100755</code> means a regular executable file.

Git records the executable bit as part of the tracked file metadata. Therefore, adding or removing executable permission can appear as a modification even when the file contents are identical. Git’s diff format explicitly reports these changes as <code>old mode</code> and <code>new mode</code>.

'''Diagnosis'''

Use the following command to check whether the reported changes are file mode changes only:

<pre>
git diff --summary
</pre>

Example output:

<pre>
mode change 100644 => 100755 scripts/deploy.sh
</pre>

You can also inspect the full diff:

<pre>
git diff
</pre>

If the output contains only <code>old mode</code> and <code>new mode</code>, without added or removed content lines, the change is caused by the executable bit rather than file contents.

Check the current repository setting with: <ref>[https://git-scm.com/docs/git-config?utm_source=chatgpt.com Git - git-config Documentation]</ref>

<pre>
git config --get core.fileMode
</pre>

To see which configuration file defines the value:

<pre>
git config --show-origin --get core.fileMode
</pre>

'''Cause'''

The behavior is controlled by Git’s <code>core.fileMode</code> setting.

When it is set to <code>true</code>, Git checks whether the executable bit in the working tree differs from the mode stored in the Git index. This can create unexpected changes when:

* A file was modified using <code>chmod +x</code> or <code>chmod -x</code>.
* A repository was copied between Linux, macOS, Windows, a network drive, or another file system with different permission behavior.
* An archive, synchronization tool, or shared folder changed executable permissions.
* A container or deployment process rewrote file modes.

Git’s documentation notes that some file systems may not reliably preserve executable-bit information, which is why <code>core.fileMode</code> can be disabled when those mode differences should not be trusted.

'''Solution'''

To ignore executable-permission changes in the current repository, run:

<pre>
git config core.fileMode false
</pre>

This is the recommended scope when the issue affects only one repository. The setting is saved in that repository’s <code>.git/config</code> file.

To apply the setting to all repositories for the current user:

<pre>
git config --global core.fileMode false
</pre>

The global setting is stored in the user-level Git configuration and acts as a fallback unless a repository overrides it.

Verify the effective value:

<pre>
git config --get core.fileMode
</pre>

The expected output is:

<pre>
false
</pre>

Then check the repository again:

<pre>
git status
git diff --summary
</pre>

Permission-only changes should no longer appear as unstaged modifications.

'''Restore File Mode Tracking'''

To restore executable-bit tracking for the current repository:

<pre>
git config core.fileMode true
</pre>

To remove the repository-specific override and return to the global or system default:

<pre>
git config --unset core.fileMode
</pre>

To restore tracking globally:

<pre>
git config --global core.fileMode true
</pre>

'''When the Executable Bit Should Be Committed'''

Do not disable <code>core.fileMode</code> merely to hide a legitimate permission change.

For shell scripts, deployment scripts, Git hooks, command-line tools, and other files that must be executable after checkout, record the executable bit in Git intentionally:

<pre>
chmod +x scripts/deploy.sh
git add scripts/deploy.sh
git commit -m "Mark deploy script as executable"
</pre>

The committed mode change will appear as:

<pre>
mode change 100644 => 100755 scripts/deploy.sh
</pre>

If the local file system cannot apply <code>chmod</code> correctly, update the Git index directly:

<pre>
git update-index --chmod=+x scripts/deploy.sh
git commit -m "Mark deploy script as executable"
</pre>

To remove executable status from the Git index:

<pre>
git update-index --chmod=-x scripts/deploy.sh
</pre>

Git provides index-level support for explicitly overriding a tracked file’s executable bit.

{{exclaim}} Notice: Setting <code>core.fileMode=false</code> does not change the actual operating-system permissions and does not rewrite previously committed file modes. It only tells Git not to treat executable-bit differences in the working tree as modifications. Use a repository-level setting unless the same problem consistently affects all repositories on the machine.