Datalab SimpleRemoteProxy - `get_cdl_xmlrpc_port()` reads the wrong INI file (DataLab ≥ 1.3)

[ThomasMalletCodra]

Symptom

SimpleRemoteProxy() in autoconnect mode (no port= argument, no DATALAB_XMLRPCPORT environment variable) fails to reach a running DataLab 1.3:

• on a machine that has been running DataLab since ≤ 1.2: the client connects to a stale port left over in the legacy INI file, then raises ConnectionRefusedError: Unable to connect to DataLab after 5.0s;
• on a fresh DataLab 1.3 installation: the legacy INI file never exists, so the client raises ConnectionRefusedError: DataLab has not yet been executed or no valid configuration found.

This is the documented headline use case (control DataLab from Spyder or a Jupyter notebook), so the impact is user-visible even though the blast radius is narrow.

Root cause

sigima/client/remote.py::get_cdl_xmlrpc_port() probes these candidates, in order:

folder	file
.DataLab_v3	DataLab_v3.ini
.DataLab_v2	DataLab_v2.ini
.DataLab_v1	DataLab_v1.ini
.DataLab	DataLab.ini (v0.x legacy)

But since DataLab 1.3, the configuration is written to a typed INI file:

• datalab/config/appinfo.py — TYPED_CONFIG_SUFFIX = "_typed" and get_typed_config_filename() → <basedir>/.DataLab_v1/DataLab_v1_typed.ini
• datalab/config/persistence.py — DataLabUserConfig.filename() returns <name>_typed.ini
• the non-typed file is now read-only: _LegacyConfigReader.save() is a no-op (it exists only for the 1.2 → 1.3 migration)
• the port is written by datalab/gui/main.py through save_runtime_option(Conf, "rpc_server_port"), i.e. into the typed file

Observed on a real machine (2026-08-19):

file	last write	[main] rpc_server_port
~/.DataLab_v1/DataLab_v1.ini	2026-08-17	60887 ← stale, still read by Sigima
~/.DataLab_v1/DataLab_v1_typed.ini	2026-08-19	60766 ← current, ignored

The section ([main]) and the key (rpc_server_port) are unchanged; only the file name differs.

Proposed fix

Try the typed file before the legacy one, for each version folder. Keep the legacy fallbacks so that a Sigima client still works against DataLab 1.2 and 0.x.

# sigima/client/remote.py

def get_cdl_xmlrpc_port():
    """Return DataLab current XML-RPC port. ..."""
    if sys.platform == "win32" and "HOME" in os.environ:
        os.environ.pop("HOME")  # Avoid getting old WinPython settings dir

    config_basedir = get_config_basedir()

    # Configuration folders to try, newest major version first. For each folder,
    # the typed file (DataLab >= 1.3) takes precedence over the legacy one, which
    # is no longer written and may hold a stale port.
    config_folders = [".DataLab_v3", ".DataLab_v2", ".DataLab_v1", ".DataLab"]

    for folder_name in config_folders:
        basename = folder_name.lstrip(".")
        for ini_name in (f"{basename}_typed.ini", f"{basename}.ini"):
            fname = osp.join(config_basedir, folder_name, ini_name)
            if not osp.exists(fname):
                continue
            ini = cp.ConfigParser()
            try:
                ini.read(fname)
                return ini.get("main", "rpc_server_port")
            except (cp.NoSectionError, cp.NoOptionError):
                continue

    raise ConnectionRefusedError(
        "DataLab has not yet been executed or no valid configuration found"
    )

Note the behaviour change beyond the file name: a candidate that exists but has no rpc_server_port key must fall through to the next candidate instead of aborting the folder — the current code already does continue, keep it.

Suggested test

In sigima/tests/common/client_unit_test.py (or a new client_port_discovery_unit_test.py), monkeypatch guidata.userconfig.get_config_basedir to a tmp_path and assert:

1. typed file only → returns its port;
2. both files present with different ports → returns the typed one;
3. legacy file only → returns its port (backward compatibility with DataLab ≤ 1.2);
4. typed file present but without rpc_server_port → falls back to the legacy file;
5. nothing present → raises ConnectionRefusedError.