From 9e352a886f30279ba73aa2f40ab457e2c40473d5 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 9 Dec 2025 17:30:26 +0000
Subject: [PATCH 1/8] Initial plan


From 45619043957ff852d0648024fad9a51cf49b8d57 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 9 Dec 2025 17:51:40 +0000
Subject: [PATCH 2/8] Add miniforge3 support to replace deprecated mambaforge

Co-authored-by: humitos <244656+humitos@users.noreply.github.com>
---
 docs/user/config-file/v2.rst                  |  3 ++
 readthedocs/builds/constants_docker.py        |  3 ++
 readthedocs/config/config.py                  |  2 +-
 readthedocs/config/tests/test_config.py       | 33 +++++++++++++++++++
 readthedocs/doc_builder/director.py           | 33 ++++++++++++-------
 .../rtd_tests/fixtures/spec/v2/schema.json    |  5 ++-
 6 files changed, 66 insertions(+), 13 deletions(-)

diff --git a/docs/user/config-file/v2.rst b/docs/user/config-file/v2.rst
index 51f519530eb..20e31118394 100644
--- a/docs/user/config-file/v2.rst
+++ b/docs/user/config-file/v2.rst
@@ -327,6 +327,9 @@ You can use several interpreters and versions, from CPython, Miniconda, and Mamb
   - ``mambaforge-22.9``
   - ``mambaforge-23.11``
   - ``mambaforge-latest`` (alias for the latest version available on Read the Docs)
+  - ``miniforge3-24.11``
+  - ``miniforge3-25.1``
+  - ``miniforge3-latest`` (alias for the latest version available on Read the Docs)
 
 build.tools.nodejs
 ``````````````````
diff --git a/readthedocs/builds/constants_docker.py b/readthedocs/builds/constants_docker.py
index 17ef655f0fc..635bd95cee4 100644
--- a/readthedocs/builds/constants_docker.py
+++ b/readthedocs/builds/constants_docker.py
@@ -46,6 +46,8 @@
             "mambaforge-4.10": "mambaforge-4.10.3-10",
             "mambaforge-22.9": "mambaforge-22.9.0-3",
             "mambaforge-23.11": "mambaforge-23.11.0-0",
+            "miniforge3-24.11": "miniforge3-24.11.2-1",
+            "miniforge3-25.1": "miniforge3-25.1.1-2",
         },
         "nodejs": {
             "14": "14.21.3",
@@ -98,6 +100,7 @@
 _TOOLS["python"]["latest"] = _TOOLS["python"]["3"]
 _TOOLS["python"]["miniconda-latest"] = _TOOLS["python"]["miniconda3-3.12-24.9"]
 _TOOLS["python"]["mambaforge-latest"] = _TOOLS["python"]["mambaforge-23.11"]
+_TOOLS["python"]["miniforge3-latest"] = _TOOLS["python"]["miniforge3-25.1"]
 _TOOLS["nodejs"]["latest"] = _TOOLS["nodejs"]["24"]
 _TOOLS["ruby"]["latest"] = _TOOLS["ruby"]["3.4"]
 _TOOLS["rust"]["latest"] = _TOOLS["rust"]["1.91"]
diff --git a/readthedocs/config/config.py b/readthedocs/config/config.py
index e1df084e2de..8c4ee397376 100644
--- a/readthedocs/config/config.py
+++ b/readthedocs/config/config.py
@@ -218,7 +218,7 @@ def python_interpreter(self):
         tool = self.build.tools.get("python")
         if tool and tool.version.startswith("mamba"):
             return "mamba"
-        if tool and tool.version.startswith("miniconda"):
+        if tool and (tool.version.startswith("miniconda") or tool.version.startswith("miniforge")):
             return "conda"
         if tool:
             return "python"
diff --git a/readthedocs/config/tests/test_config.py b/readthedocs/config/tests/test_config.py
index bb62c4125b2..d0741a2f2a1 100644
--- a/readthedocs/config/tests/test_config.py
+++ b/readthedocs/config/tests/test_config.py
@@ -335,6 +335,39 @@ def test_conda_key_not_required_for_conda_mamba_when_build_commands(self):
         with does_not_raise(ConfigError):
             build.validate()
 
+    def test_conda_key_required_for_miniforge3(self):
+        build = get_build_config(
+            {
+                "build": {
+                    "os": "ubuntu-22.04",
+                    "tools": {
+                        "python": "miniforge3-24.11",
+                    },
+                },
+            }
+        )
+        with raises(ConfigError) as excinfo:
+            build.validate()
+        assert excinfo.value.message_id == ConfigError.CONDA_KEY_REQUIRED
+        assert excinfo.value.format_values.get("key") == "conda"
+
+    def test_conda_key_not_required_for_miniforge3_when_build_commands(self):
+        build = get_build_config(
+            {
+                "build": {
+                    "os": "ubuntu-22.04",
+                    "tools": {
+                        "python": "miniforge3-25.1",
+                    },
+                    "commands": [
+                        "conda env create --file environment.yml",
+                    ],
+                },
+            }
+        )
+        with does_not_raise(ConfigError):
+            build.validate()
+
     @pytest.mark.parametrize("value", [3, [], "invalid"])
     def test_conda_check_invalid_value(self, value):
         build = get_build_config({"conda": value})
diff --git a/readthedocs/doc_builder/director.py b/readthedocs/doc_builder/director.py
index d212b0e5c9f..adc1e15927a 100644
--- a/readthedocs/doc_builder/director.py
+++ b/readthedocs/doc_builder/director.py
@@ -622,17 +622,28 @@ def install_build_tools(self):
                 )
                 # If the tool version selected is not available from the
                 # cache we compile it at build time
-                cmd = [
-                    # TODO: make ``PYTHON_CONFIGURE_OPTS="--enable-shared"``
-                    # environment variable to work here. Note that
-                    # ``self.build_environment.run`` does not support passing
-                    # environment for a particular command:
-                    # https://github.com/readthedocs/readthedocs.org/blob/9d2d1a2/readthedocs/doc_builder/environments.py#L430-L431
-                    "asdf",
-                    "install",
-                    tool,
-                    full_version,
-                ]
+                
+                # For miniforge3, unset CONDA_ENVS_PATH and CONDA_DEFAULT_ENV
+                # environment variables to allow proper installation
+                # See https://github.com/readthedocs/readthedocs.org/issues/11690
+                if tool == "python" and full_version.startswith("miniforge3"):
+                    cmd = [
+                        "/bin/sh",
+                        "-c",
+                        f"unset CONDA_ENVS_PATH ; unset CONDA_DEFAULT_ENV ; asdf install {tool} {full_version}",
+                    ]
+                else:
+                    cmd = [
+                        # TODO: make ``PYTHON_CONFIGURE_OPTS="--enable-shared"``
+                        # environment variable to work here. Note that
+                        # ``self.build_environment.run`` does not support passing
+                        # environment for a particular command:
+                        # https://github.com/readthedocs/readthedocs.org/blob/9d2d1a2/readthedocs/doc_builder/environments.py#L430-L431
+                        "asdf",
+                        "install",
+                        tool,
+                        full_version,
+                    ]
                 self.build_environment.run(
                     *cmd,
                 )
diff --git a/readthedocs/rtd_tests/fixtures/spec/v2/schema.json b/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
index 8ad1ba0f19a..85b68ade2de 100644
--- a/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
+++ b/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
@@ -203,7 +203,10 @@
                 "mambaforge-4.10",
                 "mambaforge-22.9",
                 "mambaforge-23.11",
-                "mambaforge-latest"
+                "mambaforge-latest",
+                "miniforge3-24.11",
+                "miniforge3-25.1",
+                "miniforge3-latest"
               ]
             },
             "nodejs": {

From 2560b663649e656a22fd9bc60313cc25823ffca3 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 9 Dec 2025 18:00:42 +0000
Subject: [PATCH 3/8] Add test for miniforge3 python_interpreter property

Co-authored-by: humitos <244656+humitos@users.noreply.github.com>
---
 readthedocs/config/tests/test_config.py | 33 +++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/readthedocs/config/tests/test_config.py b/readthedocs/config/tests/test_config.py
index d0741a2f2a1..6f3caa71906 100644
--- a/readthedocs/config/tests/test_config.py
+++ b/readthedocs/config/tests/test_config.py
@@ -368,6 +368,39 @@ def test_conda_key_not_required_for_miniforge3_when_build_commands(self):
         with does_not_raise(ConfigError):
             build.validate()
 
+    def test_miniforge3_python_interpreter(self, tmpdir):
+        apply_fs(
+            tmpdir,
+            {
+                "readthedocs.yml": """
+                version: 2
+                build:
+                  os: ubuntu-22.04
+                  tools:
+                    python: miniforge3-24.11
+                conda:
+                  environment: environment.yml
+                """,
+                "environment.yml": "name: test",
+            },
+        )
+        build = get_build_config(
+            {
+                "build": {
+                    "os": "ubuntu-22.04",
+                    "tools": {
+                        "python": "miniforge3-24.11",
+                    },
+                },
+                "conda": {
+                    "environment": "environment.yml",
+                },
+            },
+            source_file=str(tmpdir.join("readthedocs.yml")),
+        )
+        build.validate()
+        assert build.python_interpreter == "conda"
+
     @pytest.mark.parametrize("value", [3, [], "invalid"])
     def test_conda_check_invalid_value(self, value):
         build = get_build_config({"conda": value})

From 06d245113f8f4c1b248e90fbbe99969b028cfa7a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 9 Dec 2025 18:03:06 +0000
Subject: [PATCH 4/8] Fix security issue: use shlex.quote to prevent command
 injection

Co-authored-by: humitos <244656+humitos@users.noreply.github.com>
---
 readthedocs/doc_builder/director.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/readthedocs/doc_builder/director.py b/readthedocs/doc_builder/director.py
index adc1e15927a..1cca8d5bfc3 100644
--- a/readthedocs/doc_builder/director.py
+++ b/readthedocs/doc_builder/director.py
@@ -10,6 +10,7 @@
 
 import datetime
 import os
+import shlex
 import tarfile
 
 import structlog
@@ -630,7 +631,7 @@ def install_build_tools(self):
                     cmd = [
                         "/bin/sh",
                         "-c",
-                        f"unset CONDA_ENVS_PATH ; unset CONDA_DEFAULT_ENV ; asdf install {tool} {full_version}",
+                        f"unset CONDA_ENVS_PATH ; unset CONDA_DEFAULT_ENV ; asdf install {shlex.quote(tool)} {shlex.quote(full_version)}",
                     ]
                 else:
                     cmd = [

From fe37623704f1b2f68ea29017265ab5893786a50f Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 10 Dec 2025 09:46:59 +0000
Subject: [PATCH 5/8] Remove miniforge3-24.11, mark mambaforge as deprecated
 per feedback

Co-authored-by: humitos <244656+humitos@users.noreply.github.com>
---
 docs/user/config-file/v2.rst                       | 9 ++++-----
 readthedocs/builds/constants_docker.py             | 1 -
 readthedocs/config/tests/test_config.py            | 6 +++---
 readthedocs/rtd_tests/fixtures/spec/v2/schema.json | 1 -
 4 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/docs/user/config-file/v2.rst b/docs/user/config-file/v2.rst
index 20e31118394..b34e78a13e6 100644
--- a/docs/user/config-file/v2.rst
+++ b/docs/user/config-file/v2.rst
@@ -323,11 +323,10 @@ You can use several interpreters and versions, from CPython, Miniconda, and Mamb
   - ``miniconda3-3.12-24.1``
   - ``miniconda3-3.12-24.9``
   - ``miniconda-latest`` (alias for the latest version available on Read the Docs)
-  - ``mambaforge-4.10``
-  - ``mambaforge-22.9``
-  - ``mambaforge-23.11``
-  - ``mambaforge-latest`` (alias for the latest version available on Read the Docs)
-  - ``miniforge3-24.11``
+  - ``mambaforge-4.10`` (deprecated)
+  - ``mambaforge-22.9`` (deprecated)
+  - ``mambaforge-23.11`` (deprecated)
+  - ``mambaforge-latest`` (deprecated - alias for the latest version available on Read the Docs)
   - ``miniforge3-25.1``
   - ``miniforge3-latest`` (alias for the latest version available on Read the Docs)
 
diff --git a/readthedocs/builds/constants_docker.py b/readthedocs/builds/constants_docker.py
index 635bd95cee4..c01303971dd 100644
--- a/readthedocs/builds/constants_docker.py
+++ b/readthedocs/builds/constants_docker.py
@@ -46,7 +46,6 @@
             "mambaforge-4.10": "mambaforge-4.10.3-10",
             "mambaforge-22.9": "mambaforge-22.9.0-3",
             "mambaforge-23.11": "mambaforge-23.11.0-0",
-            "miniforge3-24.11": "miniforge3-24.11.2-1",
             "miniforge3-25.1": "miniforge3-25.1.1-2",
         },
         "nodejs": {
diff --git a/readthedocs/config/tests/test_config.py b/readthedocs/config/tests/test_config.py
index 6f3caa71906..be4b2a57088 100644
--- a/readthedocs/config/tests/test_config.py
+++ b/readthedocs/config/tests/test_config.py
@@ -341,7 +341,7 @@ def test_conda_key_required_for_miniforge3(self):
                 "build": {
                     "os": "ubuntu-22.04",
                     "tools": {
-                        "python": "miniforge3-24.11",
+                        "python": "miniforge3-25.1",
                     },
                 },
             }
@@ -377,7 +377,7 @@ def test_miniforge3_python_interpreter(self, tmpdir):
                 build:
                   os: ubuntu-22.04
                   tools:
-                    python: miniforge3-24.11
+                    python: miniforge3-25.1
                 conda:
                   environment: environment.yml
                 """,
@@ -389,7 +389,7 @@ def test_miniforge3_python_interpreter(self, tmpdir):
                 "build": {
                     "os": "ubuntu-22.04",
                     "tools": {
-                        "python": "miniforge3-24.11",
+                        "python": "miniforge3-25.1",
                     },
                 },
                 "conda": {
diff --git a/readthedocs/rtd_tests/fixtures/spec/v2/schema.json b/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
index 85b68ade2de..0b77fb3c1c6 100644
--- a/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
+++ b/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
@@ -204,7 +204,6 @@
                 "mambaforge-22.9",
                 "mambaforge-23.11",
                 "mambaforge-latest",
-                "miniforge3-24.11",
                 "miniforge3-25.1",
                 "miniforge3-latest"
               ]

From 5204d260a6872fd04ad515a05e2994c6328f5f9e Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 10 Dec 2025 10:15:55 +0000
Subject: [PATCH 6/8] Update to miniforge3-25.11 and improve env var handling
 per feedback

Co-authored-by: humitos <244656+humitos@users.noreply.github.com>
---
 docs/user/config-file/v2.rst                  |  2 +-
 readthedocs/builds/constants_docker.py        |  4 +-
 readthedocs/config/tests/test_config.py       |  8 +--
 readthedocs/doc_builder/director.py           | 55 ++++++++++---------
 .../rtd_tests/fixtures/spec/v2/schema.json    |  2 +-
 5 files changed, 37 insertions(+), 34 deletions(-)

diff --git a/docs/user/config-file/v2.rst b/docs/user/config-file/v2.rst
index b34e78a13e6..ad9be3ce398 100644
--- a/docs/user/config-file/v2.rst
+++ b/docs/user/config-file/v2.rst
@@ -327,7 +327,7 @@ You can use several interpreters and versions, from CPython, Miniconda, and Mamb
   - ``mambaforge-22.9`` (deprecated)
   - ``mambaforge-23.11`` (deprecated)
   - ``mambaforge-latest`` (deprecated - alias for the latest version available on Read the Docs)
-  - ``miniforge3-25.1``
+  - ``miniforge3-25.11``
   - ``miniforge3-latest`` (alias for the latest version available on Read the Docs)
 
 build.tools.nodejs
diff --git a/readthedocs/builds/constants_docker.py b/readthedocs/builds/constants_docker.py
index c01303971dd..ff3abc19738 100644
--- a/readthedocs/builds/constants_docker.py
+++ b/readthedocs/builds/constants_docker.py
@@ -46,7 +46,7 @@
             "mambaforge-4.10": "mambaforge-4.10.3-10",
             "mambaforge-22.9": "mambaforge-22.9.0-3",
             "mambaforge-23.11": "mambaforge-23.11.0-0",
-            "miniforge3-25.1": "miniforge3-25.1.1-2",
+            "miniforge3-25.11": "miniforge3-25.11.0-1",
         },
         "nodejs": {
             "14": "14.21.3",
@@ -99,7 +99,7 @@
 _TOOLS["python"]["latest"] = _TOOLS["python"]["3"]
 _TOOLS["python"]["miniconda-latest"] = _TOOLS["python"]["miniconda3-3.12-24.9"]
 _TOOLS["python"]["mambaforge-latest"] = _TOOLS["python"]["mambaforge-23.11"]
-_TOOLS["python"]["miniforge3-latest"] = _TOOLS["python"]["miniforge3-25.1"]
+_TOOLS["python"]["miniforge3-latest"] = _TOOLS["python"]["miniforge3-25.11"]
 _TOOLS["nodejs"]["latest"] = _TOOLS["nodejs"]["24"]
 _TOOLS["ruby"]["latest"] = _TOOLS["ruby"]["3.4"]
 _TOOLS["rust"]["latest"] = _TOOLS["rust"]["1.91"]
diff --git a/readthedocs/config/tests/test_config.py b/readthedocs/config/tests/test_config.py
index be4b2a57088..424c116579c 100644
--- a/readthedocs/config/tests/test_config.py
+++ b/readthedocs/config/tests/test_config.py
@@ -341,7 +341,7 @@ def test_conda_key_required_for_miniforge3(self):
                 "build": {
                     "os": "ubuntu-22.04",
                     "tools": {
-                        "python": "miniforge3-25.1",
+                        "python": "miniforge3-25.11",
                     },
                 },
             }
@@ -357,7 +357,7 @@ def test_conda_key_not_required_for_miniforge3_when_build_commands(self):
                 "build": {
                     "os": "ubuntu-22.04",
                     "tools": {
-                        "python": "miniforge3-25.1",
+                        "python": "miniforge3-25.11",
                     },
                     "commands": [
                         "conda env create --file environment.yml",
@@ -377,7 +377,7 @@ def test_miniforge3_python_interpreter(self, tmpdir):
                 build:
                   os: ubuntu-22.04
                   tools:
-                    python: miniforge3-25.1
+                    python: miniforge3-25.11
                 conda:
                   environment: environment.yml
                 """,
@@ -389,7 +389,7 @@ def test_miniforge3_python_interpreter(self, tmpdir):
                 "build": {
                     "os": "ubuntu-22.04",
                     "tools": {
-                        "python": "miniforge3-25.1",
+                        "python": "miniforge3-25.11",
                     },
                 },
                 "conda": {
diff --git a/readthedocs/doc_builder/director.py b/readthedocs/doc_builder/director.py
index 1cca8d5bfc3..99be7f501ce 100644
--- a/readthedocs/doc_builder/director.py
+++ b/readthedocs/doc_builder/director.py
@@ -10,7 +10,6 @@
 
 import datetime
 import os
-import shlex
 import tarfile
 
 import structlog
@@ -623,28 +622,17 @@ def install_build_tools(self):
                 )
                 # If the tool version selected is not available from the
                 # cache we compile it at build time
-                
-                # For miniforge3, unset CONDA_ENVS_PATH and CONDA_DEFAULT_ENV
-                # environment variables to allow proper installation
-                # See https://github.com/readthedocs/readthedocs.org/issues/11690
-                if tool == "python" and full_version.startswith("miniforge3"):
-                    cmd = [
-                        "/bin/sh",
-                        "-c",
-                        f"unset CONDA_ENVS_PATH ; unset CONDA_DEFAULT_ENV ; asdf install {shlex.quote(tool)} {shlex.quote(full_version)}",
-                    ]
-                else:
-                    cmd = [
-                        # TODO: make ``PYTHON_CONFIGURE_OPTS="--enable-shared"``
-                        # environment variable to work here. Note that
-                        # ``self.build_environment.run`` does not support passing
-                        # environment for a particular command:
-                        # https://github.com/readthedocs/readthedocs.org/blob/9d2d1a2/readthedocs/doc_builder/environments.py#L430-L431
-                        "asdf",
-                        "install",
-                        tool,
-                        full_version,
-                    ]
+                cmd = [
+                    # TODO: make ``PYTHON_CONFIGURE_OPTS="--enable-shared"``
+                    # environment variable to work here. Note that
+                    # ``self.build_environment.run`` does not support passing
+                    # environment for a particular command:
+                    # https://github.com/readthedocs/readthedocs.org/blob/9d2d1a2/readthedocs/doc_builder/environments.py#L430-L431
+                    "asdf",
+                    "install",
+                    tool,
+                    full_version,
+                ]
                 self.build_environment.run(
                     *cmd,
                 )
@@ -776,11 +764,26 @@ def get_build_env_vars(self):
         env["NO_COLOR"] = "1"
 
         if self.data.config.conda is not None:
+            # Check if we are using miniforge3
+            # Only add CONDA_ENVS_PATH and CONDA_DEFAULT_ENV if we are not using miniforge.
+            # See https://github.com/readthedocs/readthedocs.org/issues/11690
+            using_miniforge = False
+            for _, version in self.data.config.build.tools.items():
+                if version.full_version.startswith("miniforge"):
+                    using_miniforge = True
+                    break
+
+            if not using_miniforge:
+                env.update(
+                    {
+                        # NOTE: should these be prefixed with "READTHEDOCS_"?
+                        "CONDA_ENVS_PATH": os.path.join(self.data.project.doc_path, "conda"),
+                        "CONDA_DEFAULT_ENV": self.data.version.slug,
+                    }
+                )
+
             env.update(
                 {
-                    # NOTE: should these be prefixed with "READTHEDOCS_"?
-                    "CONDA_ENVS_PATH": os.path.join(self.data.project.doc_path, "conda"),
-                    "CONDA_DEFAULT_ENV": self.data.version.slug,
                     "BIN_PATH": os.path.join(
                         self.data.project.doc_path,
                         "conda",
diff --git a/readthedocs/rtd_tests/fixtures/spec/v2/schema.json b/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
index 0b77fb3c1c6..06458bac859 100644
--- a/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
+++ b/readthedocs/rtd_tests/fixtures/spec/v2/schema.json
@@ -204,7 +204,7 @@
                 "mambaforge-22.9",
                 "mambaforge-23.11",
                 "mambaforge-latest",
-                "miniforge3-25.1",
+                "miniforge3-25.11",
                 "miniforge3-latest"
               ]
             },

From 4a56846930994ac705afb11fa18ae94b5a4bb9d6 Mon Sep 17 00:00:00 2001
From: Manuel Kaufmann <humitos@gmail.com>
Date: Wed, 10 Dec 2025 11:33:06 +0100
Subject: [PATCH 7/8] Revert unseting `CONDA_` variables because it's not
 needed

The build-tool is pre-compiled, so there is no need to unset these.
I tested this locally and it worked fine.
---
 readthedocs/doc_builder/director.py | 21 +++------------------
 1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/readthedocs/doc_builder/director.py b/readthedocs/doc_builder/director.py
index 99be7f501ce..d212b0e5c9f 100644
--- a/readthedocs/doc_builder/director.py
+++ b/readthedocs/doc_builder/director.py
@@ -764,26 +764,11 @@ def get_build_env_vars(self):
         env["NO_COLOR"] = "1"
 
         if self.data.config.conda is not None:
-            # Check if we are using miniforge3
-            # Only add CONDA_ENVS_PATH and CONDA_DEFAULT_ENV if we are not using miniforge.
-            # See https://github.com/readthedocs/readthedocs.org/issues/11690
-            using_miniforge = False
-            for _, version in self.data.config.build.tools.items():
-                if version.full_version.startswith("miniforge"):
-                    using_miniforge = True
-                    break
-
-            if not using_miniforge:
-                env.update(
-                    {
-                        # NOTE: should these be prefixed with "READTHEDOCS_"?
-                        "CONDA_ENVS_PATH": os.path.join(self.data.project.doc_path, "conda"),
-                        "CONDA_DEFAULT_ENV": self.data.version.slug,
-                    }
-                )
-
             env.update(
                 {
+                    # NOTE: should these be prefixed with "READTHEDOCS_"?
+                    "CONDA_ENVS_PATH": os.path.join(self.data.project.doc_path, "conda"),
+                    "CONDA_DEFAULT_ENV": self.data.version.slug,
                     "BIN_PATH": os.path.join(
                         self.data.project.doc_path,
                         "conda",

From 2d4fd192589e76190d8318668c16c70eaae0fe80 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 10 Dec 2025 10:43:40 +0000
Subject: [PATCH 8/8] Simplify test_miniforge3_python_interpreter test per
 feedback

Co-authored-by: humitos <244656+humitos@users.noreply.github.com>
---
 readthedocs/config/tests/test_config.py | 18 +-----------------
 1 file changed, 1 insertion(+), 17 deletions(-)

diff --git a/readthedocs/config/tests/test_config.py b/readthedocs/config/tests/test_config.py
index 424c116579c..558cb1ba506 100644
--- a/readthedocs/config/tests/test_config.py
+++ b/readthedocs/config/tests/test_config.py
@@ -368,22 +368,7 @@ def test_conda_key_not_required_for_miniforge3_when_build_commands(self):
         with does_not_raise(ConfigError):
             build.validate()
 
-    def test_miniforge3_python_interpreter(self, tmpdir):
-        apply_fs(
-            tmpdir,
-            {
-                "readthedocs.yml": """
-                version: 2
-                build:
-                  os: ubuntu-22.04
-                  tools:
-                    python: miniforge3-25.11
-                conda:
-                  environment: environment.yml
-                """,
-                "environment.yml": "name: test",
-            },
-        )
+    def test_miniforge3_python_interpreter(self):
         build = get_build_config(
             {
                 "build": {
@@ -396,7 +381,6 @@ def test_miniforge3_python_interpreter(self, tmpdir):
                     "environment": "environment.yml",
                 },
             },
-            source_file=str(tmpdir.join("readthedocs.yml")),
         )
         build.validate()
         assert build.python_interpreter == "conda"