the owncloud-client package includes an option to add a .desktop entry
to $HOME/.configure/autostart/, which allows it to autostart when you
log in to your desktop environment. Because the full path of the binary
is in the .desktop file, it will always start THAT copy of
owncloud-client, even if it is garbage collected.

(ins)efraim@macbook41 ~/workspace/guix$ guix build --no-grafts owncloud-client
/gnu/store/61779fqfpwap9wwf2y5yidq4qciihq1i-owncloud-client-2.3.4
(ins)efraim@macbook41 ~/workspace/guix$ head -n8 /gnu/store/61779fqfpwap9wwf2y5yidq4qciihq1i-owncloud-client-2.3.4/share/applications/owncloud.desktop
[Desktop Entry]
Categories=Utility;X-SuSE-SyncUtility;
Type=Application
Exec=/gnu/store/61779fqfpwap9wwf2y5yidq4qciihq1i-owncloud-client-2.3.4/bin/owncloud
Name=ownCloud desktop sync client
Comment=ownCloud desktop synchronization client
GenericName=Folder Sync
Icon=owncloud

-- 
Efraim Flashner   <efraim@flashner.co.il>   אפרים פלשנר
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