Make in-source build error message more human readable.
Make in-source build error message more human readable.

git-svn-id: 31cbfd89c62d6b8b302bb3be5c74ebef9d32ffd0@1331 01035d8c-6547-0410-b346-abe4f91aad63

freedv/freedv,freedv/freedv,freedv/freedv