Update BUILD.md

support official rocksdb6.x series

BUILD.md

@@ -3,16 +3,16 @@ Execute this series of commands to compile MongoDB with RocksDB storage engine:
 install compression libraries (zlib, bzip2, snappy):
 sudo apt-get install zlib1g-dev; sudo apt-get install libbz2-dev; sudo apt-get install libsnappy-dev
 # get rocksdb
-git clone https://github.com/wolfkdy/rocksdb.git
-git checkout fb5.18_totdb
+git clone https://github.com/facebook/rocksdb.git
+git checkout main
 # compile rocksdb
 cd rocksdb; USE_RTTI=1 CFLAGS=-fPIC make static_lib; sudo INSTALL_PATH=/usr make install; cd ..
 # get mongo
 git clone https://github.com/mongodb/mongo.git
 git checkout tags/r4.2.5 -b branch_tags_4.2.5
 # get mongorocks
 git clone https://github.com/mongodb-partners/mongo-rocks
-git checkout v4.2.5_rc2
+git checkout master
 # add rocksdb module to mongo
 mkdir -p mongo/src/mongo/db/modules/
 ln -sf ~/mongo-rocks mongo/src/mongo/db/modules/rocks