.DELETE_ON_ERROR doc

[jidanni]

(info "(make) Errors") says

      Usually when a command fails, if it has changed the target file at
   all, the file is corrupted and cannot be used--or at least it is not
   completely updated.  Yet the file's time stamp says that it is now up to
   date, so the next time `make' runs, it will not try to update that
   file.  The situation is just the same as when the command is killed by a
   signal; *note Interrupts::.  So generally the right thing to do is to
   delete the target file if the command fails after beginning to change
   the file.  `make' will do this if `.DELETE_ON_ERROR' appears as a
   target.  This is almost always what you want `make' to do, but it is
   not historical practice; so for compatibility, you must explicitly
   request it.

I find I don't have to explicitly request it.

Or maybe it is only talking about interrupts.