Developer setups for user D-Bus service files?

[Friedrich W. H. Kossebau]

Hi,

(plasma-devel as CC: for heads-up, please reply only to kde-devel to keep 
discussion in one place)

at least with systemd controlled start (but possibly also before) of the 
session D-Bus (based on what I understood so far, please correct me) for a 
user is not possible just by editing their user's config files to control 
where the session D-Bus instance is looking at, e.g. to find user-deployed D-
Bus service files.

Anything is configured by things only an admin can modify.

Which brings some challenges for installing D-Bus service files when 
installing user-built things into a user-selected prefix, like in case of 
usual KDE developer setups (e.g. ~/kde/usr as used in documentation):

a) typically the D-Bus session will not see those and thus be unable to start 
any service described in them, thus things being broken

b) there is no option to override any service files already found in system 
dirs before, D-Bus does a first-found-rules approach

While for a) in typical distribution setups as user one can deploy D-Bus 
service files to ~/.local/share (like when session D-Bus is configured with 
<standard_session_servicedirs /> which results in XDG_DATA_ROOT dir being 
checked, which in the system usually is not set (remember, user configs are 
not read here), thus resolves to default ~/.local/share), this does not help 
with b) in case one wants to work on an app/service also installed to the 
system, as the D-Bus service files hard-code the binary path.


YOUR INPUT NEEDED
So, what standard approach should we take as developers here? Ideally we all 
do something similar, so any issues hit are more easy to understand/reproduce 
when we discuss them.

The goal should be to add the recommended approach to the developer 
documentation and make any build tools (like kdesrc-build) also deal with that 
as much as possible.

No own proposal here, only found out about the challenge now (even if it seems 
as old as D-Bus is).

Cheers
Friedrich