Eigen stamp and tmp directories appearing in the install directory #402
Description
When I try to build and install TiledArray, I noticed that src/eigen-stamp and tmp directories are appearing in my installation directory. From what I understand, these are not needed for the installation and should instead appear under build/_deps alongside eigen-src and eigen-build.
The location of these directories can be controlled using the STAMP_DIR and TMP_DIR options of ExternalProject_Add in external/eigen.cmake.