Use mamba 2 for the base installation of Miniforge

Miniforge3/construct.yaml

@@ -1,9 +1,9 @@
-{% set version = os.environ.get("MINIFORGE_VERSION", "24.11.3-0") %}
-{% set conda_libmamba_solver_version = "24.9.0"%}
-# when mamba_version is updated here, also update MICROMAMBA_VERSION in scripts/build.sh
-# As of Dec 2024 -- mamba 2.0.5 isn't compatible with constructor
-# https://github.com/conda-forge/miniforge/issues/697
-{% set mamba_version = "1.5.12" %}
+{% set version = os.environ.get("MINIFORGE_VERSION", "24.11.3-1") %}
+{% set conda_libmamba_solver_version = "25.1.0"%}
+# When `mamba_version` is updated here, also update the value of:
+#   - `MICROMAMBA_VERSION` in `scripts/build.sh`
+#   - `MAMBA_VERSION` in `scripts/test.sh`
+{% set mamba_version = "2.0.6.rc1" %}
 
 name: Miniforge3
 version: {{ version }}
@@ -29,15 +29,15 @@ initialize_by_default: False
 user_requested_specs:
   - python 3.12.*
   - conda >={{ version.split("-")[0] }}
-  - mamba >={{ mamba_version }}
+  - conda-forge/label/mamba_prerelease::mamba==2.0.6.rc1
   - pip
   # Omit conda-libmamba-solver so that conda is free to remove it later
   - miniforge_console_shortcut 1.*  # [win]
 
 specs:
   - python 3.12.*
   - conda {{ version.split("-")[0] }}
-  - mamba {{ mamba_version }}
+  - conda-forge/label/mamba_prerelease::mamba==2.0.6.rc1
   - conda-libmamba-solver {{ conda_libmamba_solver_version }}
   - pip
   - miniforge_console_shortcut 1.*  # [win]

scripts/build.sh

@@ -14,7 +14,7 @@ echo "***** Install constructor *****"
 mamba install --yes \
     --channel conda-forge --override-channels \
     jinja2 curl libarchive \
-    "constructor>=3.9.3"
+    "constructor>=3.11.1"
 
 if [[ "$(uname)" == "Darwin" ]]; then
     mamba install --yes \
@@ -38,7 +38,7 @@ cp LICENSE "${TEMP_DIR}/"
 ls -al "${TEMP_DIR}"
 
 if [[ "${TARGET_PLATFORM}" != win-* ]]; then
-    MICROMAMBA_VERSION=1.5.11
+    MICROMAMBA_VERSION=2.0.6.rc1
     MICROMAMBA_BUILD=0
     mkdir "${TEMP_DIR}/micromamba"
     pushd "${TEMP_DIR}/micromamba"

scripts/test.sh

@@ -5,6 +5,7 @@ set -ex
 echo "***** Start: Testing Miniforge installer *****"
 
 export CONDA_PATH="${HOME}/miniforge"
+export MAMBA_VERSION="${MAMBA_VERSION:-2.0.6.rc1}"
 
 CONSTRUCT_ROOT="${CONSTRUCT_ROOT:-${PWD}}"
 
@@ -72,6 +73,28 @@ EOF
   conda list
 fi
 
+echo "+ Mamba does not warn (check that there is no warning on stderr) and returns exit code 0"
+mamba --help 2> stderr.log || cat stderr.log
+test ! -s stderr.log
+rm -f stderr.log
+
+echo "+ mamba info"
+mamba info
+
+echo "+ mamba config sources"
+mamba config sources
+
+echo "+ mamba config list"
+mamba config list
+
+echo "+ Testing mamba version (i.e. ${MAMBA_VERSION})"
+mamba info --json | python -c "import sys, json; info = json.loads(sys.stdin.read()); assert info['mamba version'] == '${MAMBA_VERSION}', info"
+echo "  OK"
+
+echo "+ Testing mamba channels"
+mamba info --json | python -c "import sys, json; info = json.loads(sys.stdin.read()); assert any('conda-forge' in c for c in info['channels']), info"
+echo "  OK"
+
 echo "***** Python path *****"
 python -c "import sys; print(sys.executable)"
 python -c "import sys; assert 'miniforge' in sys.executable"
@@ -84,3 +107,44 @@ python -c "import platform; print(platform.machine())"
 python -c "import platform; print(platform.release())"
 
 echo "***** Done: Testing installer *****"
+
+echo "***** Testing the usage of mamba main commands *****"
+
+echo "***** Initialize the current session for mamba *****"
+export MAMBA_ROOT_PREFIX="/root/miniforge"
+eval "$(mamba shell hook --shell bash)"
+
+echo "***** Create a new environment *****"
+ENV_PREFIX="/tmp/testenv"
+
+mamba create -p $ENV_PREFIX numpy --yes -vvv
+
+echo "***** Activate the environment with mamba *****"
+mamba activate $ENV_PREFIX
+
+echo "***** Check that numpy is installed with mamba list *****"
+mamba list | grep numpy
+
+echo "***** Deactivate the environment *****"
+mamba deactivate
+
+echo "***** Activate the environment with conda *****"
+conda activate $ENV_PREFIX
+
+echo "***** Check that numpy is installed with python *****"
+python -c "import numpy; print(numpy.__version__)"
+
+echo "***** Remove numpy *****"
+mamba remove numpy --yes
+
+echo "***** Check that numpy is not installed with mamba list *****"
+mamba list | grep -v numpy
+
+echo "***** Deactivate the environment with conda *****"
+conda deactivate
+
+echo "***** Remove the environment *****"
+mamba env remove -p $ENV_PREFIX --yes
+
+echo "***** Done: Testing mamba main commands *****"
+