On 03.08.17 12:07, Sönke Ludwig wrote:

By default, DUB will choose the first configuration that matches the
selected (or host) platform. So with the proper "platforms" directives,
it should work without any explicit configuration selection.

thanks a lot for this explanation.
the following fills my needs now (for linux, osx and my linux-on-raspi):

...
mainSourceFile "source/app.d"
configuration "application-osx" {
platforms "osx"
targetPath "out/osx"
lflags "-Lout/osx"
}

configuration "application-linux" {
platforms "linux-x86" "linux-x86_64"
targetPath "out/linux"
lflags "-Lout/linux"
}

configuration "application-raspi" {
platforms "arm"
targetPath "out/raspi"
lflags "-Lout/raspi"
}
...

still i do not know how to come up with proper platforms. e.g. linux-x86
is not described here:
http://dlang.org/spec/version.html#PredefinedVersions and "arm" is also
not quite right :)

cK