message: Inject mongoc source directory for building libmongocrypt
  Based on mongodb/mongo-c-driver@5b91ef0fadf4d0b536be69d47bb1bd7cfb056f63
diff: @@ -63,6 +63,7 @@ fi
  . .evergreen/find_cmake.sh
  cd $DIR
  +MONGOC_DIR="$(pwd)"
  if [ -f /proc/cpuinfo ]; then
  CONCURRENCY=$(grep -c ^processor /proc/cpuinfo)
  @@ -84,6 +85,7 @@ case "$OS" in
  cygwin*)
  GENERATOR=${GENERATOR:-"Visual Studio 14 2015 Win64"}
  CMAKE_BUILD_OPTS="/maxcpucount:$CONCURRENCY"
  + MONGOC_DIR=$(cygpath -m "$MONGOC_DIR")
  ;;
  *)
  @@ -105,7 +107,9 @@ git clone https://github.com/mongodb/libmongocrypt
  mkdir libmongocrypt/cmake_build
  cd libmongocrypt/cmake_build
  git checkout $MONGOCRYPT_VERSION
  -"$CMAKE" -G "$GENERATOR" -DENABLE_SHARED_BSON=ON -DCMAKE_INSTALL_PREFIX="$PREFIX" -DCMAKE_PREFIX_PATH="$PREFIX" -DCMAKE_BUILD_TYPE="Debug" -DENABLE_CLIENT_SIDE_ENCRYPTION=OFF ..
  +"$CMAKE" -G "$GENERATOR" -DENABLE_SHARED_BSON=ON -DCMAKE_INSTALL_PREFIX="$PREFIX" \
  + -DCMAKE_PREFIX_PATH="$PREFIX" -DCMAKE_BUILD_TYPE="Debug" \
  + -DMONGOCRYPT_MONGOC_DIR="$MONGOC_DIR" -DENABLE_CLIENT_SIDE_ENCRYPTION=OFF ..
  "$CMAKE" --build . --config Debug -- $CMAKE_BUILD_OPTS
  "$CMAKE" --build . --config Debug --target install
  cd ../../$DIR
  