Building zsh/db/gdbm on MacOS Sequoia

I recently updated XCode and installed gdbm from MacPorts in order to
run the latest tests.  After enabling zsh/db/gdbm in config.modules
with link=static I ran

./configure --enable-gdbm --disable-dynamic --enable-zsh-debug --enable-pcre

Unfortunately even after running this, "make" does not add "-lgdbm" to
the loader flags.  PCRE is also from ports, and it gets handled
correctly.  I'm using

make EXTRA_LDFLAGS=-lgdbm

to avoid the link errors, but it seems like I shouldn't need to?  What
did I miss?