CVS HEAD: "make install" broken for vpath

With current sources, it appears that vpath builds (i.e. separate source 
and build trees) are broken. "make" succeeds, but "make install" produces:

[neilc:/Users/neilc/build-pgsql]% make install
make -C doc install
make[1]: Nothing to be done for `install'.
make -C src install
make -C port install
make[2]: Nothing to be done for `install'.
make -C timezone install
make -C ../../src/port all
make[3]: Nothing to be done for `all'.
./zic -d /Users/neilc/local/pgsql-cvs/share/timezone data/africa 
data/antarctica data/asia data/australasia data/europe data/northamerica 
data/southamerica data/pacificnew data/etcetera data/factory 
data/backward data/systemv data/solar87 data/solar88 data/solar89
./zic: Can't open data/africa: No such file or directory
make[2]: *** [install] Error 1
make[1]: *** [install] Error 2
make: *** [install] Error 2

-Neil