fix: precedence for rc files, CONDARC/MAMBARC env vars

holzman · jjerphan · commit 89d2d2486327 · 2025-12-08T15:42:29.000+01:00
This code changes the rc file precedence to match the documentation
and fixes a bug where if CONDARC or MAMBARC were set that it was
ignoring all other configuration files.
diff --git a/docs/source/user_guide/configuration.rst b/docs/source/user_guide/configuration.rst
@@ -118,14 +118,27 @@ RC files have their own precedence order and use the same resolution process as
         { root_prefix }/condarc
         { root_prefix }/condarc.d
         { root_prefix }/.mambarc
+
+	{ $XDG_CONFIG_HOME | ~/.config}/conda/.condarc
+	{ $XDG_CONFIG_HOME | ~/.config}/conda/condarc
+	{ $XDG_CONFIG_HOME | ~/.config}/condarc.d
         ~/.conda/.condarc
         ~/.conda/condarc
         ~/.conda/condarc.d
         ~/.condarc
+
+        { $XDG_CONFIG_HOME | ~/.config}/mamba/.mambarc
+        { $XDG_CONFIG_HOME | ~/.config}/mamba/mambarc
+	{ $XDG_CONFIG_HOME | ~/.config}/mamba/mambarc.d
+        ~/.mamba/.mambarc
+        ~/.mamba/mambarc
+        ~/.mamba/mambarc.d
         ~/.mambarc
+
         { target_prefix }/.condarc
         { target_prefix }/condarc
         { target_prefix }/condarc.d
         { target_prefix }/.mambarc
+
         $CONDARC,
         $MAMBARC;
diff --git a/libmamba/src/api/configuration.cpp b/libmamba/src/api/configuration.cpp
@@ -2030,9 +2030,10 @@ namespace mamba
                     not be considered as logs (see log_level).)")));
 
         // Config
+
+        // MAMBARC/CONDARC env dirs get parsed in target/root prefix hooks
         insert(Configurable("rc_files", std::vector<fs::u8path>({}))
                    .group("Config sources")
-                   .set_env_var_names({ "MAMBARC", "CONDARC" })
                    .needs({ "no_rc" })
                    .set_post_merge_hook<std::vector<fs::u8path>>(
                        [this](std::vector<fs::u8path>& value)
@@ -2093,12 +2094,6 @@ namespace mamba
     // Precedence is initially set least to most, and then at the end the list is reversed.
     // Configuration::set_rc_values iterates over all config options, and then over all config
     // file source. Essentially first come first serve.
-    // just FYI re "../conda": env::user_config_dir's default value is $XDG_CONFIG_HOME/mamba
-    // But we wanted to also allow $XDG_CONFIG_HOME/conda and '..' seems like the best way to
-    // make it conda/mamba compatible. Otherwise I would have to set user_config_dir to either
-    // be just $XDG_CONFIG_HOME and always supply mamba after calling it, or I would have to
-    // give env::user_config_dir a mamba argument, all so I can supply conda in a few default
-    // cases. It seems like ../conda is an easier solution
     //
     std::vector<fs::u8path>
     Configuration::compute_default_rc_sources(const Context& context, const RCConfigLevel& level)
@@ -2143,18 +2138,11 @@ namespace mamba
                 conda_user.push_back(fs::u8path(xgd_config_home) / "conda" / path);
             }
         }
-        if (util::get_env("CONDA_PREFIX"))
-        {
-            const std::string conda_prefix = util::get_env("CONDA_PREFIX").value();
-            for (const auto& path : condarc_list)
-            {
-                conda_user.push_back(fs::u8path(conda_prefix) / path);
-            }
-        }
 
+        std::vector<fs::u8path> env_var;
         if (util::get_env("CONDARC"))
         {
-            conda_user.push_back(fs::u8path(util::get_env("CONDARC").value()));
+            env_var.push_back(fs::u8path(util::get_env("CONDARC").value()));
         }
 
         std::vector<fs::u8path> mamba_user = {
@@ -2168,7 +2156,7 @@ namespace mamba
         };
         if (util::get_env("MAMBARC"))
         {
-            mamba_user.push_back(fs::u8path(util::get_env("MAMBARC").value()));
+            env_var.push_back(fs::u8path(util::get_env("MAMBARC").value()));
         }
 
         std::vector<fs::u8path> prefix = { context.prefix_params.target_prefix / ".condarc",
@@ -2216,6 +2204,7 @@ namespace mamba
             insertIntoSources(prefix);
         }
 
+        insertIntoSources(env_var);
         // Sort by precedence
         std::reverse(sources.begin(), sources.end());
 
diff --git a/micromamba/tests/test_config.py b/micromamba/tests/test_config.py
@@ -10,6 +10,33 @@
 
 from . import helpers
 
+all_rc_files_list = [
+    # TODO: test system located sources?
+    # "/etc/conda/.condarc",
+    # "/etc/conda/condarc",
+    # "/etc/conda/condarc.d/",
+    # "/etc/conda/.mambarc",
+    # "/var/lib/conda/.condarc",
+    # "/var/lib/conda/condarc",
+    # "/var/lib/conda/condarc.d/",
+    # "/var/lib/conda/.mambarc",
+    ("root_prefix", ".condarc"),
+    ("root_prefix", "condarc"),
+    ("root_prefix", "condarc.d"),
+    ("root_prefix", ".mambarc"),
+    ("home", ".conda/.condarc"),
+    ("home", ".conda/condarc"),
+    ("home", ".conda/condarc.d"),
+    ("home", ".condarc"),
+    ("env_set_xdg", "mambarc"),
+    ("user_config_dir", "mambarc"),
+    ("home", ".mambarc"),
+    ("prefix", ".condarc"),
+    ("prefix", "condarc"),
+    ("prefix", "condarc.d"),
+    ("prefix", ".mambarc"),
+]
+
 
 @pytest.fixture
 def user_config_dir(tmp_home: Path):
@@ -59,6 +86,41 @@ def rc_file_text(rc_file_args):
     return yaml.dump(rc_file_args, Dumper=Dumper)
 
 
+def create_rc_file(
+    where,
+    rc_filename,
+    rc_file_text,
+    tmp_home,
+    tmp_root_prefix,
+    tmp_prefix,
+    tmp_path,
+    user_config_dir,
+    monkeypatch,
+):
+    if where == "home":
+        rc_file = tmp_home / rc_filename
+    elif where == "root_prefix":
+        rc_file = tmp_root_prefix / rc_filename
+    elif where == "prefix":
+        rc_file = tmp_prefix / rc_filename
+    elif where == "user_config_dir":
+        rc_file = user_config_dir / rc_filename
+    elif where == "env_set_xdg":
+        monkeypatch.setenv("XDG_CONFIG_HOME", str(tmp_home / "custom_xdg_config_dir"))
+        rc_file = tmp_home / "custom_xdg_config_dir" / "mamba" / rc_filename
+    elif where == "absolute":
+        rc_file = Path(rc_filename)
+    else:
+        raise ValueError("Bad rc file location")
+    if rc_file.suffix == ".d":
+        rc_file = rc_file / "test.yaml"
+
+    rc_file.parent.mkdir(parents=True, exist_ok=True)
+    rc_file.write_text(rc_file_text)
+
+    return rc_file
+
+
 @pytest.fixture
 def rc_file(
     request,
@@ -68,6 +130,7 @@ def rc_file(
     tmp_prefix,
     tmp_path,
     user_config_dir,
+    monkeypatch,
 ):
     """Parametrizable fixture to create an rc file at the desired location.
 
@@ -76,33 +139,55 @@ def rc_file(
     """
     if hasattr(request, "param"):
         where, rc_filename = request.param
-        if where == "home":
-            rc_file = tmp_home / rc_filename
-        elif where == "root_prefix":
-            rc_file = tmp_root_prefix / rc_filename
-        elif where == "prefix":
-            rc_file = tmp_prefix / rc_filename
-        elif where == "user_config_dir":
-            rc_file = user_config_dir / rc_filename
-        elif where == "env_set_xdg":
-            os.environ["XDG_CONFIG_HOME"] = str(tmp_home / "custom_xdg_config_dir")
-            rc_file = tmp_home / "custom_xdg_config_dir" / "mamba" / rc_filename
-        elif where == "absolute":
-            rc_file = Path(rc_filename)
-        else:
-            raise ValueError("Bad rc file location")
-        if rc_file.suffix == ".d":
-            rc_file = rc_file / "test.yaml"
     else:
-        rc_file = tmp_path / "umamba/config.yaml"
-
-    rc_file.parent.mkdir(parents=True, exist_ok=True)
-    with open(rc_file, "w+") as f:
-        f.write(rc_file_text)
+        where, rc_filename = ("absolute", tmp_path / "umamba/config.yaml")
+
+    rc_file = create_rc_file(
+        where,
+        rc_filename,
+        rc_file_text,
+        tmp_home,
+        tmp_root_prefix,
+        tmp_prefix,
+        tmp_path,
+        user_config_dir,
+        monkeypatch,
+    )
 
     return rc_file
 
 
+@pytest.fixture
+def all_rc_files(
+    rc_file_text, tmp_home, tmp_root_prefix, tmp_prefix, tmp_path, user_config_dir, monkeypatch
+):
+    """Fixture to create all rc files
+
+    The files are created in isolated folders and set as the prefix, root prefix, and
+    home folder.
+
+    """
+
+    files = []
+    for where, filename in all_rc_files_list:
+        if where == "user_config_dir":
+            continue  # redundant with XDG_HOME_DIR
+        f = create_rc_file(
+            where,
+            filename,
+            rc_file_text,
+            tmp_home,
+            tmp_root_prefix,
+            tmp_prefix,
+            tmp_path,
+            user_config_dir,
+            monkeypatch,
+        )
+
+        files.append(f)
+    return files
+
+
 class TestConfig:
     def test_config_empty(self, tmp_home):
         assert "Configuration of micromamba" in config()
@@ -140,34 +225,9 @@ def test_config_sources_empty(self, tmp_prefix, quiet_flag, norc):
             res = config("sources", quiet_flag)
             assert res.startswith("Configuration files (by precedence order):")
 
-    # TODO: test system located sources?
     @pytest.mark.parametrize(
         "rc_file",
-        (
-            # "/etc/conda/.condarc",
-            # "/etc/conda/condarc",
-            # "/etc/conda/condarc.d/",
-            # "/etc/conda/.mambarc",
-            # "/var/lib/conda/.condarc",
-            # "/var/lib/conda/condarc",
-            # "/var/lib/conda/condarc.d/",
-            # "/var/lib/conda/.mambarc",
-            ("user_config_dir", "mambarc"),
-            ("env_set_xdg", "mambarc"),
-            ("home", ".conda/.condarc"),
-            ("home", ".conda/condarc"),
-            ("home", ".conda/condarc.d"),
-            ("home", ".condarc"),
-            ("home", ".mambarc"),
-            ("root_prefix", ".condarc"),
-            ("root_prefix", "condarc"),
-            ("root_prefix", "condarc.d"),
-            ("root_prefix", ".mambarc"),
-            ("prefix", ".condarc"),
-            ("prefix", "condarc"),
-            ("prefix", "condarc.d"),
-            ("prefix", ".mambarc"),
-        ),
+        all_rc_files_list,
         indirect=True,
     )
     @pytest.mark.parametrize("rc_file_args", ({"override_channels_enabled": True},), indirect=True)
@@ -177,6 +237,28 @@ def test_config_rc_file(self, rc_file, tmp_env_name):
         expected_srcs = f"Configuration files (by precedence order):\n{short_name}".splitlines()
         assert srcs == expected_srcs
 
+    @pytest.mark.parametrize("rc_file_args", ({"override_channels_enabled": True},), indirect=True)
+    def test_rc_file_precedence(
+        self, rc_file_text, all_rc_files, tmp_env_name, tmp_home, monkeypatch
+    ):
+        env_filenames = []
+        for x in ["conda", "mamba"]:
+            env_x_rc = tmp_home / f"env-{x}rc.yaml"
+            monkeypatch.setenv(f"{x.upper()}RC", f"{env_x_rc}")
+            env_x_rc.write_text(rc_file_text)
+            env_filenames.append(str(env_x_rc).replace(os.path.expanduser("~"), "~"))
+
+        srcs = config("sources", "-vvvv", "-n", tmp_env_name).strip().splitlines()
+        for rc_file in all_rc_files:
+            short_names = [
+                str(rc_file).replace(os.path.expanduser("~"), "~") for rc_file in all_rc_files
+            ]
+
+        short_names.extend(env_filenames)
+        short_names.reverse()
+
+        assert srcs[1:] == short_names
+
     @pytest.mark.parametrize(
         "rc_file",
         [("home", "somefile.yml")],
