Building Emacs outside of the source tree triggers the following
warnings from Make:
make[2]: Circular /home/e/eliz/bzr/emacs/trunk/lib-src/rcs2log<-
/home/e/eliz/bzr/emacs/trunk/lib-src/rcs2log dependency dropped.
make[2]: Circular /home/e/eliz/bzr/emacs/trunk/lib-src/vcdiff<-
/home/e/eliz/bzr/emacs/trunk/lib-src/vcdiff dependency dropped.
make[2]: Circular /home/e/eliz/bzr/emacs/trunk/lib-src/rcs-checkin<-
/home/e/eliz/bzr/emacs/trunk/lib-src/rcs-checkin dependency dropped.
make[2]: Circular /home/e/eliz/bzr/emacs/trunk/lib-src/grep-changelog<-
/home/e/eliz/bzr/emacs/trunk/lib-src/grep-changelog dependency dropped.
I think the problem is that we have both VPATH and an explicit
dependency for these files in lib-src/Makefile.in.