ep-engine make-install fails when building 1.8.1 from source tarball

checkpoint.cc:1198: error: 'add_casted_stat' was not declared in this scope
make[2]: *** [ep_la-checkpoint.lo] Error 1
make[1]: *** [install] Error 2
make: *** [make-install-ep-engine] Error 2

logs:

make -C ep-engine install
cp wrapper/wrapper wrapper/cbadm-online-restore
cp wrapper/wrapper wrapper/cbadm-online-update
cp wrapper/wrapper wrapper/cbadm-tap-registration
cp wrapper/wrapper wrapper/cbbackup
cp wrapper/wrapper wrapper/cbbackup-incremental
cp wrapper/wrapper wrapper/cbbackup-merge-incremental
cp wrapper/wrapper wrapper/cbdbconvert
cp wrapper/wrapper wrapper/cbdbmaint
cp wrapper/wrapper wrapper/cbdbupgrade
cp wrapper/wrapper wrapper/cbflushctl
cp wrapper/wrapper wrapper/cbrestore
cp wrapper/wrapper wrapper/cbstats
cp wrapper/wrapper wrapper/cbvbucketctl
make install-am
/bin/sh ./libtool --tag=CXX --mode=compile g++ -DHAVE_CONFIG_H -I. -I. -I. -ggdb3 -I../memcached/include -I/tmp/couchbase-server_src/install/include -D_THREAD_SAFE -pipe -std=gnu++98 -O3 -Werror -pedantic -Wall -Wundef -Wshadow -fdiagnostics-show-option -Wformat -fno-strict-aliasing -Wno-strict-aliasing -Wextra -Woverloaded-virtual -Wnon-virtual-dtor -Wctor-dtor-privacy -Wno-long-long -Wno-redundant-decls -MT ep_la-backfill.lo -MD -MP -MF .deps/ep_la-backfill.Tpo -c -o ep_la-backfill.lo `test -f 'backfill.cc' || echo './'`backfill.cc
libtool: compile: g++ -DHAVE_CONFIG_H -I. -I. -I. -ggdb3 -I../memcached/include -I/tmp/couchbase-server_src/install/include -D_THREAD_SAFE -pipe -std=gnu++98 -O3 -Werror -pedantic -Wall -Wundef -Wshadow -fdiagnostics-show-option -Wformat -fno-strict-aliasing -Wno-strict-aliasing -Wextra -Woverloaded-virtual -Wnon-virtual-dtor -Wctor-dtor-privacy -Wno-long-long -Wno-redundant-decls -MT ep_la-backfill.lo -MD -MP -MF .deps/ep_la-backfill.Tpo -c backfill.cc -fno-common -DPIC -o .libs/ep_la-backfill.o
mv -f .deps/ep_la-backfill.Tpo .deps/ep_la-backfill.Plo
/bin/sh ./libtool --tag=CXX --mode=compile g++ -DHAVE_CONFIG_H -I. -I. -I. -ggdb3 -I../memcached/include -I/tmp/couchbase-server_src/install/include -D_THREAD_SAFE -pipe -std=gnu++98 -O3 -Werror -pedantic -Wall -Wundef -Wshadow -fdiagnostics-show-option -Wformat -fno-strict-aliasing -Wno-strict-aliasing -Wextra -Woverloaded-virtual -Wnon-virtual-dtor -Wctor-dtor-privacy -Wno-long-long -Wno-redundant-decls -MT ep_la-checkpoint.lo -MD -MP -MF .deps/ep_la-checkpoint.Tpo -c -o ep_la-checkpoint.lo `test -f 'checkpoint.cc' || echo './'`checkpoint.cc
libtool: compile: g++ -DHAVE_CONFIG_H -I. -I. -I. -ggdb3 -I../memcached/include -I/tmp/couchbase-server_src/install/include -D_THREAD_SAFE -pipe -std=gnu++98 -O3 -Werror -pedantic -Wall -Wundef -Wshadow -fdiagnostics-show-option -Wformat -fno-strict-aliasing -Wno-strict-aliasing -Wextra -Woverloaded-virtual -Wnon-virtual-dtor -Wctor-dtor-privacy -Wno-long-long -Wno-redundant-decls -MT ep_la-checkpoint.lo -MD -MP -MF .deps/ep_la-checkpoint.Tpo -c checkpoint.cc -fno-common -DPIC -o .libs/ep_la-checkpoint.o
checkpoint.cc:7:25: error: statwriter.hh: No such file or directory
checkpoint.cc: In member function 'void CheckpointManager::addStats(void (const char*, uint16_t, const char*, uint32_t, const void*), const void*)':
checkpoint.cc:1198: error: 'add_casted_stat' was not declared in this scope
make[2]: *** [ep_la-checkpoint.lo] Error 1
make[1]: *** [install] Error 2
make: *** [make-install-ep-engine] Error 2