[Dune] Globally installed modules vs. local modules

[Lukas Böger]

Dear all,

is it generally discouraged to globally install a version of Dune
modules (e.g. stable 2.4.1) and then compile local versions besides
(e.g. current master branch)?

While doing so with a set of local modules not matching the globally
installed ones, I ran into trouble with cmake modules. They were
globally found and their paths merged into CMAKE_MODULE_PATH in
dune_create_dependency_tree, such that they had precedence over the
local dune-common/cmake/modules directory with files of a more recent
version. I guess such a mix of global and local cmake modules of
different versions can work out by accident, but not in general.

Example: globally installed dune-x, dune-y and dune-z (all 2.4.1) and
locally compile dune-x and dune-y (both current master branch), but
EXCLUDING the optional dune-z?

Setting DUNE_CONTROL_PATH doesn't help here as global paths will be
searched for modules anyway.

Best,
Lukas