Use meson instead of configure for conda install

.github/workflows/ci-conda.yml

@@ -66,21 +66,20 @@ jobs:
           conda info
           conda list
 
-      - name: Configure
+      - name: Bootstrap
         shell: bash -l {0}
-        continue-on-error: true
-        run: |
-          ./bootstrap
-          echo "::add-matcher::.github/workflows/configure-systempackage-problem-matcher.json"
-          ./configure --enable-build-as-root --with-python=$CONDA_PREFIX/bin/python --prefix=$CONDA_PREFIX --enable-system-site-packages $(for pkg in $(./sage -package list :standard: --has-file spkg-configure.m4 --has-file distros/conda.txt --exclude rpy2); do echo --with-system-$pkg=force; done)
-          echo "::remove-matcher owner=configure-system-package-warning::"
-          echo "::remove-matcher owner=configure-system-package-error::"
+        run: ./bootstrap
 
       - name: Build
         shell: bash -l {0}
         run: |
           # Use --no-deps and pip check below to verify that all necessary dependencies are installed via conda.
-          pip install --no-build-isolation --no-deps -v -v -e ./pkgs/sage-conf ./pkgs/sage-setup
+          echo "::group::sage-setup"
+          pip install --no-build-isolation --no-deps -v -v -e ./pkgs/sage-setup
+          echo "::endgroup::"
+          echo "::group::sage-conf"
+          pip install --no-build-isolation --no-deps -v -v -e ./pkgs/sage-conf_meson 
+          echo "::endgroup::"
           pip install --no-build-isolation --no-deps --config-settings editable_mode=compat -v -v -e ./src
         env:
           SAGE_NUM_THREADS: 2
@@ -95,6 +94,12 @@ jobs:
         shell: bash -l {0}
         run: ./sage -t --all -p0
 
+      # We keep this step for now to make sure that the configure-based setup still works.
+      - name: Test configure
+        shell: bash -l {0}
+        run: |
+          ./configure --enable-build-as-root --with-python=$CONDA_PREFIX/bin/python --prefix=$CONDA_PREFIX --enable-system-site-packages $(for pkg in $(./sage -package list :standard: --has-file spkg-configure.m4 --has-file distros/conda.txt --exclude rpy2); do echo --with-system-$pkg=force; done) || true
+
       - name: Print logs
         if: always()
         run: |

.gitignore

@@ -284,3 +284,6 @@ src/.coverage/
 # git worktree
 worktree*
 **/worktree*
+
+# meson build directory
+builddir

.vscode/settings.json

@@ -35,5 +35,6 @@
         "sagemath",
         "Cython"
     ],
-    "editor.formatOnType": true
+    "editor.formatOnType": true,
+    "esbonio.sphinx.confDir": ""
 }

bootstrap-conda

@@ -98,6 +98,7 @@ echo >&2 $0:$LINENO: generate conda environment files
     ) > environment-template.yml
     (
         sed 's/name: sage-build/name: sage/' environment-template.yml
+        echo "  - meson" 
         echo "  # Additional packages providing all dependencies for the Sage library"
         for pkg in $SAGELIB_SYSTEM_PACKAGES; do
             echo "  - $pkg"

meson.build

@@ -0,0 +1,10 @@
+project('sage', 'c')
+cc = meson.get_compiler('c')
+
+maxima = find_program('maxima', required: true)
+ecl_config = find_program('ecl-config', required: true)
+openmp = dependency('openmp', required : false)
+#ntl = dependency('ntl', required: true) doesn't work, so ask the compiler directly:
+ntl = cc.find_library('ntl', required: true)
+
+subdir('pkgs/sage-conf_meson')

pkgs/sage-conf/pyproject.toml

@@ -1,3 +1,10 @@
 [build-system]
 requires = ["setuptools", "wheel"]
 build-backend = "setuptools.build_meta"
+
+[project]
+name = "sage-conf"
+dynamic = ["version"]
+
+[tool.setuptools.dynamic]
+version = {file = ["VERSION.txt"]}

pkgs/sage-conf/setup.cfg

@@ -1,6 +1,5 @@
 [metadata]
 name = sage-conf
-version = file: VERSION.txt
 description = Sage: Open Source Mathematics Software: Configuration module for the SageMath library
 long_description = file: README.rst
 license = GNU General Public License (GPL) v3 or later

pkgs/sage-conf_meson/.gitignore

@@ -0,0 +1,6 @@
+/sage_conf/builddir
+/build
+/dist
+/*.egg-info
+/.tox
+/bin/sage-env-config

pkgs/sage-conf_meson/README.rst

@@ -0,0 +1 @@
+../sage-conf/README.rst

pkgs/sage-conf_meson/VERSION.txt

@@ -0,0 +1 @@
+10.2.beta8

pkgs/sage-conf_meson/meson.build

@@ -0,0 +1,32 @@
+conf_data = configuration_data()
+
+conf_data.set('PACKAGE_VERSION', '1.2.3')
+
+conf_data.set('SAGE_MAXIMA', maxima.path())
+# Conda's ecl does not have any problems with Maxima, so nothing needs to be set here:
+conf_data.set('SAGE_MAXIMA_FAS', '')
+
+# Kenzo cannot yet be provided by the system, so we always use the SAGE_LOCAL path for now.
+conf_data.set('SAGE_KENZO_FAS', '\'${prefix}\'/lib/ecl/kenzo.fas')
+
+conf_data.set('SAGE_ARB_LIBRARY', 'arb')
+
+# It can be found, so we don't have to set anything here:
+conf_data.set('NTL_INCDIR', '')
+conf_data.set('NTL_LIBDIR', '')
+
+conf_data.set('SAGE_ECL_CONFIG', ecl_config.path())
+
+conf_data.set('SAGE_ARCHFLAGS', 'unset')
+
+# not needed when using conda, as we then don't build any pc files
+conf_data.set('SAGE_PKG_CONFIG_PATH', '')
+
+if openmp.found()
+  conf_data.set('OPENMP_CFLAGS', '-fopenmp')
+  conf_data.set('OPENMP_CXXFLAGS', '-fopenmp')
+endif
+
+configure_file(input : '../sage-conf_conda/_sage_conf/_conf.py.in',
+               output : '_conf.py',
+               configuration : conf_data)

pkgs/sage-conf_meson/pyproject.toml

@@ -0,0 +1 @@
+../sage-conf/pyproject.toml

pkgs/sage-conf_meson/sage_conf/__init__.py

@@ -0,0 +1,9 @@
+import importlib
+
+from .builddir.build_info import CONDA_PREFIX
+
+conf = importlib.import_module('.builddir.pkgs.sage-conf_meson._conf', 'sage_conf')
+conf_options = [x for x in conf.__dict__ if not x.startswith("_")]
+globals().update({k: getattr(conf, k) for k in conf_options})
+
+SAGE_LOCAL = CONDA_PREFIX

pkgs/sage-conf_meson/setup.py

@@ -0,0 +1,53 @@
+import os
+import sys
+from pathlib import Path
+
+from setuptools import setup
+from setuptools.command.build_py import build_py as setuptools_build_py
+from setuptools.command.editable_wheel import (
+    editable_wheel as setuptools_editable_wheel,
+)
+from setuptools.errors import SetupError
+
+
+class build_py(setuptools_build_py):
+    def run(self):
+        here = Path(__file__).parent
+        if self.editable_mode:
+            root = here.parent.parent
+        else:
+            raise SetupError('Not supported')
+
+        conda_prefix = os.environ.get('CONDA_PREFIX', '')
+        if not conda_prefix:
+            raise SetupError(
+                'No conda environment is active. '
+                'See https://doc.sagemath.org/html/en/installation/conda.html on how to get started.'
+            )
+
+        builddir = here / "sage_conf" / "builddir"
+        cmd = f"cd {root} && meson setup {builddir} --wipe"
+        print(f"Running {cmd}")
+        sys.stdout.flush()
+        if os.system(cmd) != 0:
+            raise SetupError("configure failed")
+
+        # Write build info
+        with open(builddir / 'build_info.py', 'w', encoding="utf-8") as build_info:
+            build_info.write(f'SAGE_ROOT = "{root}"\n')
+            build_info.write(f'CONDA_PREFIX = "{conda_prefix}"\n')
+
+
+class editable_wheel(setuptools_editable_wheel):
+    r"""
+    Customized so that exceptions raised by our build_py
+    do not lead to the "Customization incompatible with editable install" message
+    """
+    _safely_run = setuptools_editable_wheel.run_command
+
+
+setup(
+    cmdclass=dict(
+        build_py=build_py, editable_wheel=editable_wheel
+    )
+)

src/doc/en/installation/conda.rst

@@ -139,9 +139,12 @@ Here we assume that you are using a git checkout.
   - Bootstrap the source tree and install the build prerequisites and the Sage library::
 
       $ ./bootstrap
-      $ pip install --no-build-isolation -v -v --editable ./pkgs/sage-conf_conda ./pkgs/sage-setup
+      $ pip install --no-build-isolation -v -v --editable ./pkgs/sage-conf_meson ./pkgs/sage-setup
       $ pip install --no-build-isolation --config-settings editable_mode=compat -v -v --editable ./src
 
+    In case of errors, try to use ``sage-conf_conda`` instead of ``sage-conf_meson``,
+    and please report the problem by opening an issue on GitHub.
+
   - Verify that Sage has been installed::
 
       $ sage -c 'print(version())'