message: fix the TINK_SRC_DIR definition in cmake_build_test.sh
diff: #!/bin/bash
  -set -ue
  +set -e
  #############################################################################
  ##### Test for using Tink in a CMake project.
  @@ -23,6 +23,14 @@ set -ue
  ## can be found.
  ## TEST_SRCDIR -- The directory in which Tink is stored.
  +if [ -z $TEST_TMPDIR ];then
  + echo "Error: You must set TEST_TMPDIR to a temporary working directory"
  + exit 1
  +fi
  +if [ -z $TEST_SRCDIR ];then
  + echo "Error: You must set TEST_SRCDIR to the directory which Tink is stored(i.e. Tink parent directory)."
  + exit 1
  +fi
  # XDG_CACHE_HOME must be set for a successful build of BoringSSL.
  export XDG_CACHE_HOME="$TEST_TMPDIR/cache"
  TEST_DATA_DIR="$TEST_SRCDIR/tink/examples/cc/helloworld"
  @@ -41,6 +49,7 @@ AAD_TEXT="some associated data"
  ##### Create necessary directories, and link Tink source.
  mkdir -p $XDG_CACHE_HOME
  mkdir -p $PROJECT_DIR $PROJECT_DIR/third_party
  +TINK_SRC_DIR="$TEST_SRCDIR/tink"
  ln -s $TINK_SRC_DIR $PROJECT_DIR/third_party/tink
  ##### Copy "my_project" files.
  