The GNU Cash package clearly *wants* to be able to use the libdbi
backends, since it pulls them in as dependencies. However, you can only
open xml formatted GNU cash files.
The CMake scripts hard-code the DVD path to be basically
<PATH_OF_LIBDBI>/dbd. However GNU Cash does check the environment
variable GNC_DBD_DIR, so I set that environment variable in the wrapper
script.
With this change, you should be able to e.g. "Save As" in the sqlite
format.
Fixes issue #57445