Unresolved symbols in nfsd in 2.4.20-pre2-ac1

[Samuel Flory]

  It looks like someone broke nfsd.  From make modules_install:

find kernel -path '*/pcmcia/*' -name '*.o' | xargs -i -r ln -sf ../{}
pcmcia
if [ -r System.map ]; then /sbin/depmod -ae -F System.map 
2.4.20-pre1-ac3; fi
depmod: *** Unresolved symbols in
/lib/modules/2.4.20-pre1-ac3/kernel/fs/nfsd/nfsd.o
depmod:         exp_readunlock
make: *** [_modinst_post] Error 1

Here's my config:
[root@grendel linux-2.4.20-pre2-ac1]# grep -i -e rpc -e nfs .config
CONFIG_NFS_FS=y
CONFIG_NFS_V3=y
CONFIG_ROOT_NFS=y
CONFIG_NFSD=m
CONFIG_NFSD_V3=y
CONFIG_NFSD_TCP=y
CONFIG_SUNRPC=y
CONFIG_NCPFS_NFS_NS=y