Add correct Python executable to Path when building arrow. (ray-proje…

…ct#820)

* Tell cmake which python to use when building arrow.

* Pass different path into cmake when building arrow so that cmake finds the right python.

* Add correct python executable to PATH when running cmake for ray.

build.sh

@@ -32,17 +32,27 @@ popd
 bash "$ROOT_DIR/src/thirdparty/download_thirdparty.sh"
 bash "$ROOT_DIR/src/thirdparty/build_thirdparty.sh" $PYTHON_EXECUTABLE
 
+# Get the directory of the Python executable.
+PYTHON_EXECUTABLE_DIR=$(dirname $PYTHON_EXECUTABLE)
+
 # Now build everything.
 pushd "$ROOT_DIR/python/ray/core"
  # We use these variables to set PKG_CONFIG_PATH, which is important so that
  # in cmake, pkg-config can find plasma.
  TP_DIR=$ROOT_DIR/src/thirdparty
  ARROW_HOME=$TP_DIR/arrow/cpp/build/cpp-install
- if [ "$VALGRIND" = "1" ]
- then
- PKG_CONFIG_PATH=$ARROW_HOME/lib/pkgconfig cmake -DCMAKE_BUILD_TYPE=Debug ../../..
+ if [[ "$VALGRIND" = "1" ]]; then
+ # Pass a slightly different path into this command so that cmake finds the
+ # right Python interpreter and libraries.
+ PATH=$PYTHON_EXECUTABLE_DIR:$PATH \
+ PKG_CONFIG_PATH=$ARROW_HOME/lib/pkgconfig \
+ cmake -DCMAKE_BUILD_TYPE=Debug ../../..
  else
- PKG_CONFIG_PATH=$ARROW_HOME/lib/pkgconfig cmake -DCMAKE_BUILD_TYPE=Release ../../..
+ # Pass a slightly different path into this command so that cmake finds the
+ # right Python interpreter and libraries.
+ PATH=$PYTHON_EXECUTABLE_DIR:$PATH \
+ PKG_CONFIG_PATH=$ARROW_HOME/lib/pkgconfig \
+ cmake -DCMAKE_BUILD_TYPE=Release ../../..
  fi
  make clean
  make -j${PARALLEL}

src/thirdparty/build_thirdparty.sh

@@ -31,6 +31,13 @@ cd $TP_DIR/arrow/cpp
 mkdir -p $TP_DIR/arrow/cpp/build
 cd $TP_DIR/arrow/cpp/build
 export ARROW_HOME=$TP_DIR/arrow/cpp/build/cpp-install
+
+# Get the directory of the Python executable.
+PYTHON_EXECUTABLE_DIR=$(dirname $PYTHON_EXECUTABLE)
+
+# Pass a slightly different path into this command so that cmake finds the right
+# Python interpreter and libraries.
+PATH=$PYTHON_EXECUTABLE_DIR:$PATH \
 cmake -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_C_FLAGS="-g -O3" \
  -DCMAKE_CXX_FLAGS="-g -O3" \