M.7.9.2 Renaming VC Work Files and Master Files

When you rename a registered file, you must also rename its master file correspondingly to get proper results. Use vc-rename-file to rename the source file as you specify, and rename its master file accordingly. It also updates any snapshots (see section M.7.8 Snapshots) that mention the file, so that they use the new name; despite this, the snapshot thus modified may not completely work (see section M.7.8.2 Snapshot Caveats).

You cannot use vc-rename-file on a file that is locked by someone else.