Working in pure environments - e.g. services like lorri [activated via home-manager `home.nix`]

When trying to work within a pure (mkShell) environment

The resulting error e.g. for services like lorri [activated via home-manager home.nix]
(while services like docker appear to work [activated in configuration.nix])

direnv: loading ~/proj/web/.envrc
Apr 25 09:21:41.991 INFO lorri daemon is not running, loading a cached environment, expr: ../shell.nix
direnv: export +IN_LORRI_SHELL +NIX_LOG_FD +allowSubstitutes +extraClosure +origArgs +origBuilder +origExtraClosure +origOutputs +origPATH +origSystem +preHook +preferLocalBuild ~HOST_PATH ~IN_NIX_SHELL ~NIX_BUILD_TOP ~NIX_CFLAGS_COMPILE ~NIX_LDFLAGS ~PATH ~buildInputs ~builder ~name ~out ~shellHook

Where could I find information on how to get a service like lorri running in a pure (mkShell) environment?