specify ln_backend_needed as needed

jmclient/jmclient/configure.py

@@ -780,6 +780,9 @@ def load_program_config(config_path="", bs=None, plugin_services=[],
     lnchans = [x for x in chans if "type" in x and x["type"] == "ln-onion"]
     # only 1; multiple directories will be in this config section:
     assert len(lnchans) < 2
+    # The additional flag 'ln_backend_needed' exists to address
+    # the case of a user with Lightning configured, but doing a non-interactive
+    # operation; in this case, starting the Lightning backend is pointless.
     if lnchans and ln_backend_needed:
         lnchanconfig = lnchans[0]
         if lnchanconfig["clightning-location"] == "bundled":

scripts/joinmarket-qt.py

@@ -2343,7 +2343,7 @@ def get_wallet_printout(wallet_service):
 
 config_load_error = False
 try:
-    load_program_config(config_path=options.datadir)
+    load_program_config(config_path=options.datadir, ln_backend_needed=True)
 except Exception as e:
     config_load_error = "Failed to setup joinmarket: "+repr(e)
     if "RPC" in repr(e):

scripts/tumbler.py

@@ -25,7 +25,7 @@ def main():
     if len(args) < 1:
         jmprint('Error: Needs a wallet file', "error")
         sys.exit(EXIT_ARGERROR)
-    load_program_config(config_path=options['datadir'])
+    load_program_config(config_path=options['datadir'], ln_backend_needed=True)
     logsdir = os.path.join(os.path.dirname(
         jm_single().config_location), "logs")
     tumble_log = get_tumble_log(logsdir)

test/ygrunner.py

@@ -260,7 +260,7 @@ def get_addr_and_fund(yg):
 
 @pytest.fixture(scope="module")
 def setup_ygrunner():
-    load_test_config()
+    load_test_config(ln_backend_needed=True)
     jm_single().bc_interface.tick_forward_chain_interval = 10
     jm_single().bc_interface.simulate_blocks()
     # handles the custom regtest hrp for bech32