Always add root_prefix/envs in envs_dirs

libmamba/src/api/configuration.cpp

@@ -965,13 +965,18 @@ namespace mamba
             }
         }
 
-        std::vector<fs::u8path> fallback_envs_dirs_hook(const Context& context)
+        void envs_dirs_hook(const Context& context, std::vector<fs::u8path>& dirs)
         {
-            return { context.prefix_params.root_prefix / "envs" };
-        }
+            // Check that "root_prefix/envs" is already in the dirs,
+            // and append if not - to match `conda`
+            // Therefore, there is no need for a fallback value anymore
+            fs::u8path default_env_dir = context.prefix_params.root_prefix / "envs";
+            if (std::find(dirs.begin(), dirs.end(), default_env_dir) == dirs.end())
+            {
+                dirs.push_back(default_env_dir);
+            }
 
-        void envs_dirs_hook(std::vector<fs::u8path>& dirs)
-        {
+            // Check that the values exist as directories
             for (auto& d : dirs)
             {
                 d = fs::weakly_canonical(util::expand_home(d.string())).string();
@@ -1297,10 +1302,10 @@ namespace mamba
                    .set_rc_configurable(RCConfigLevel::kHomeDir)
                    .set_env_var_names({ "CONDA_ENVS_DIRS" })
                    .needs({ "root_prefix" })
-                   .set_fallback_value_hook<decltype(m_context.envs_dirs)>(
-                       [this] { return detail::fallback_envs_dirs_hook(m_context); }
+                   .set_post_merge_hook<decltype(m_context.envs_dirs)>(
+                       [this](decltype(m_context.envs_dirs)& value)
+                       { return detail::envs_dirs_hook(m_context, value); }
                    )
-                   .set_post_merge_hook(detail::envs_dirs_hook)
                    .description("Possible locations of named environments"));
 
         insert(Configurable("pkgs_dirs", &m_context.pkgs_dirs)

libmamba/tests/src/core/test_configuration.cpp

@@ -538,6 +538,40 @@ namespace mamba
                               - https://repo.mamba.pm/conda-forge)"));
             }
 
+            TEST_CASE_METHOD(Configuration, "envs_dirs")
+            {
+                // Load default config
+                // `envs_dirs` should be set to `root_prefix / envs`
+                config.load();
+
+                const auto& envs_dirs = config.at("envs_dirs").value<std::vector<fs::u8path>>();
+                REQUIRE(envs_dirs.size() == 1);
+                REQUIRE(
+                    envs_dirs[0]
+                    == util::path_concat(
+                        std::string(config.at("root_prefix").value<mamba::fs::u8path>()),
+                        "envs"
+                    )
+                );
+            }
+
+            TEST_CASE_METHOD(Configuration, "envs_dirs_with_additional_rc")
+            {
+                std::string cache1 = util::path_concat(util::user_home_dir(), "foo_envs_dirs");
+                std::string rc1 = "envs_dirs:\n  - " + cache1;
+
+                load_test_config(rc1);
+
+                REQUIRE(
+                    config.dump()
+                    == "envs_dirs:\n  - " + cache1 + "\n  - "
+                           + util::path_concat(
+                               std::string(config.at("root_prefix").value<mamba::fs::u8path>()),
+                               "envs"
+                           )
+                );
+            }
+
             TEST_CASE_METHOD(Configuration, "pkgs_dirs")
             {
                 std::string cache1 = util::path_concat(util::user_home_dir(), "foo");

micromamba/src/common_options.hpp

@@ -40,9 +40,6 @@ init_channel_parser(CLI::App* subcom, mamba::Configuration& config);
 void
 load_channel_options(mamba::Context& ctx);
 
-void
-channels_hook(std::vector<std::string>& channels);
-
 void
 override_channels_hook(mamba::Configuration& config, bool& override_channels);