address review comments

README.md

@@ -87,17 +87,19 @@ dependencies for a given platform.
 The following setup scripts use the `DEPENDENCY_DIR` environment variable to set the
 location to download and build packages. This defaults to `deps-download` in the current
 working directory.
+
 Use `INSTALL_PREFIX` to set the install directory of the packages. This defaults to
 `deps-install` in the current working directory on macOS and to the default install
 location (eg. `/usr/local`) on linux.
 Using the default install location `/usr/local` on macOS is discouraged since this
 location is used by certain Homebrew versions.
 
-You will have to manually add the `INSTALL_PREFIX` value in the IDE or bash environment,
+Manually add the `INSTALL_PREFIX` value in the IDE or bash environment,
 say `export INSTALL_PREFIX=/Users/$USERNAME/velox/deps-install` to `~/.zshrc` so that
-Velox builds can use the installed packages.
-You can also reuse this install for Velox clients such as Prestissimo by specifying a
-common location.
+subsequent Velox builds can use the installed packages.
+
+*You can reuse `DEPENDENCY_INSTALL` and `INSTALL_PREFIX` for Velox clients such as Prestissimo
+by specifying a common shared directory.`*
 
 ### Setting up on macOS
 

scripts/setup-macos.sh

@@ -81,10 +81,12 @@ function install_build_prerequisites {
     python3 -m venv ${PYTHON_VENV}
   fi
   source ${PYTHON_VENV}/bin/activate; pip3 install cmake-format regex pyyaml
-  curl -L https://github.com/ccache/ccache/releases/download/v4.10.2/ccache-4.10.2-darwin.tar.gz > ccache.tar.gz
-  tar -xf ccache.tar.gz
-  mv ccache-4.10.2-darwin/ccache /usr/local/bin/
-  rm -rf ccache-4.10.2-darwin ccache.tar.gz
+  if [ ! -f /usr/local/bin/ccache ]; then
+    curl -L https://github.com/ccache/ccache/releases/download/v4.10.2/ccache-4.10.2-darwin.tar.gz > ccache.tar.gz
+    tar -xf ccache.tar.gz
+    mv ccache-4.10.2-darwin/ccache /usr/local/bin/
+    rm -rf ccache-4.10.2-darwin ccache.tar.gz
+  fi
 }
 
 function install_velox_deps_from_brew {
@@ -173,5 +175,5 @@ function install_velox_deps {
   fi
 )
 
-echo 'To add cmake-format bin to your $PATH, consider adding this to your ~/.profile:'
-echo 'Please add $INSTALL_PREFIX to your ~/.zshrc'
+echo "To reuse the installed dependencies for subsequent builds, consider adding this to your ~/.zshrc"
+echo "export INSTALL_PREFIX=$INSTALL_PREFIX"