Existing file does not exist?!?

[Hiebert, Darren \(MS\)]

I am debugging a complicated makefile (i.e. make -d) using make-3.81 to follow its decisions.

One strange thing is that it is reporting one particular file this way:

Considering target file `myfile'.
  File `myfile' does not exist.

However, I know this file exists. Furthermore, even after invoking the rule that would create the file, make still reports that it does not exist.

Under what circumstances can a file be reported by make as not existing when it does exist?