I get an error from 'scons install' while building from source for 2.8.0rc2.

My build commands are:
scons --prefix=/b/mongo280rc2 -j4 all > o.all
scons --prefix=/b/mongo280rc2 -j4 install

The error is from 'scons install' :
Source `src/mongo-tools/bsondump' not found, needed by target `/b/mongo280rc2/bin/bsondump'.
scons: building terminated because of errors.

bsondump doesn't occur in the 'scons all' output:
grep bsondump o.all -> nothing

And it isn't in the build result:
ls build/linux2/normal/mongo/ | grep -v \.a
bson
bson_check_test
bson_field_test
bsonobjbuilder_test
bson_obj_test
builder_test
buildinfo.cpp
buildinfo.o
client
config_server_tests
crypto
curop_test
db
dbclient_rs_test
dbtest
dbtests
expression_geo_test
expression_test
expression_text_test
logger
md5_test
mongo
mongobridge
mongod
mongoperf
mongos
mr_test
oid_test
pch.o
processinfo_test
s
scoped_db_conn_test
scripting
server_options_test
shell
sock_test
spin_lock_test
stringutils_test
text_test
tools
unittest
util