Debugging file sync issues

Symptoms

After doing some modifications to a file or directory outside of an IDE and switching back, the changes are not visible in a Project View tree or an editor.

Before reporting

1. Make sure "Settings | Appearance & Behavior | System Settings | Synchronize files on frame activation" option is enabled.
2. Syncing file changes takes some time. Make sure there is no spinning "Synchronizing ..." indicator in the lower left corner of the IDE window before looking for updates.
3. Check that the issue isn't caused by UI. For example, if you can't find a new file in a tree, check whether collapsing/expanding a parent node reveals it.

Collecting logs

1. Locate the log directory (Help | Show Logs).
2. Shut down the IDE.
3. Delete everything from the log directory.

4. Paste the following lines into bin/log.xml file above the "root" tag:

     <category name="#com.intellij.openapi.vfs.newvfs.RefreshSession">
       <priority value="TRACE"/>
     </category>
     <category name="#com.intellij.openapi.vfs.impl.local.NativeFileWatcherImpl">
       <priority value="TRACE"/>
     </category>
     <category name="#com.intellij.openapi.vfs.newvfs.persistent.RefreshWorker">
       <priority value="TRACE"/>
     </category>
   
   

5. Start the IDE, open a project, make a change to a file or a directory, note a time.
6. Switch back to the IDE, wait until syncing is finished, then archive everything from the log directory.

When reporting an issue, provide collected logs, time of a file change, a path to the file or directory that was modified, and a nature of a change.

After

When done, don't forget to restore the bin/log.xml file and restart - otherwise, excessive logging may slow down the IDE.