Error during 'make installworld' over NFS

For years I've been doing upgrades by mounting /usr/src and /usr/obj via
read-only NFS shares, and doing an installkernel/installworld/
mergemaster sequence.

Lately I've built stable/14-n267062-77205dbc1397 but I'm hitting an
error that appears to be because the NFS mounts are read-only.


[... snip ...]
installing DIRS testsFILESDIR
install  -d -m 0755 -o root  -g wheel  //usr/tests/sbin/dhclient
--- option-domain-search_test.install ---
(cd /usr/src/sbin/dhclient/tests &&  DEPENDFILE=.depend.option-domain-search_test  NO_SUBDIR=1 make -f /usr/src/sbin/dhclient/tests/Makefile _RECURSING_PROGS=t   PROG=option-domain-search_test  install)
--- realinstall_subdir_kerberos5 ---
rm -f //usr/share/man/man3/heim_ntlm_encode_type2.3 //usr/share/man/man3/heim_ntlm_encode_type2.3.gz;  install -l h -o root -g wheel -m 444  //usr/share/man/man3/ntlm_core.3.gz //usr/share/man/man3/heim_ntlm_encode_type2.3.gz
--- realinstall_subdir_include ---
mktemp: mkstemp failed on osreldate.LksVOanR: Read-only file system

make[2]: stopped in /usr/src
      105.91 real        36.49 user        25.68 sys
*** [installworld] Error code 2

make[1]: stopped in /usr/src
1 error

make[1]: stopped in /usr/src

make: stopped in /usr/src



Thanks in advance for any suggestions.



Jim