doc/dev/macos.rst: update to be in sync with master

* we've moved to cmake 3.5, so no need to hack for newer cmake
* nss dependency is dropped, no need to install it anymore
* pass clang and clang++ using cmake variable to be more consistent
* pass CMAKE_EXE_LINKER_FLAGS as `/usr/local/opt/llvm/lib` is
  not in default library paths.
* mention boostorg/atomic#15

Signed-off-by: Kefu Chai <kchai@redhat.com>

doc/dev/macos.rst

@@ -7,23 +7,21 @@ Since we've switched to C++ 17, and the default clang shipped with Xcode 9 does
 
 and install all the necessary bits::
 
-  brew install nss snappy ccache cmake pkg-config
+  brew install snappy ccache cmake pkg-config
   pip install cython
 
 install FUSE if you want to build the FUSE support::
 
   brew cask install osxfuse
 
-apply the patch at https://gist.github.com/tchaikov/c3f324a7c36fc9774739cea319d5c49b , to address https://public.kitware.com/Bug/view.php?id=15943 . We cannot bump up the required cmake version yet, because RHEL/CentOS does not have the newer cmake yet.
-
 then, under the source directory of Ceph::
 
   mkdir build
   cd build
-  PKG_CONFIG_PATH=/usr/local/Cellar/nss/3.33/lib/pkgconfig \
-    CC=/usr/local/opt/llvm/bin/clang \
-    CXX=/usr/local/opt/llvm/bin/clang++ \
-    cmake .. -DBOOST_J=4 \
+  cmake .. -DBOOST_J=4 \
+    -DCMAKE_C_COMPILER=/usr/local/opt/llvm/bin/clang \
+    -DCMAKE_CXX_COMPILER=/usr/local/opt/llvm/bin/clang++ \
+    -DCMAKE_EXE_LINKER_FLAGS="-L/usr/local/opt/llvm/lib" \
     -DENABLE_GIT_VERSION=OFF \
     -DWITH_MANPAGE=OFF \
     -DWITH_LIBCEPHFS=OFF \
@@ -34,8 +32,10 @@ then, under the source directory of Ceph::
     -DWITH_BLUESTORE=OFF \
     -DWITH_RADOSGW=OFF \
     -DWITH_SPDK=OFF \
-    -DSNAPPY_ROOT_DIR=/usr/local/Cellar/snappy/1.1.7
+    -DSNAPPY_ROOT_DIR=/usr/local/Cellar/snappy/1.1.7_1
 
 The paths to ``nss`` and ``snappy`` might vary if newer versions of the packages are installed.
 
+Also, please consider using boost v1.69 to address the bug of https://github.com/boostorg/atomic/issues/15.
+
 Currently, the most practical uses for Ceph on MacOS might be FUSE and some other librados based applications.