When I run spack env activate ..., Spack automatically adds all of my packages to my PATH, but it doesn't set all environment variables. In particular, when I build gdal+java+mdb, it adds a lot of Java dependencies to the environment. These dependencies cannot be found unless CLASSPATH is set. I could hack Spack Environments to set CLASSPATH, but it would be more robust and predictable if Spack Environments set the same env vars that were written to module files.

@zchen105