Meta: Install libsemigroups before building sdist

This change is sub-optimal, since libsemigroups is
not required to build an sdist; however,
libsemigroups is required to build the wheels.

With the setup we have (using setuptools as a
build-backend), there is no out-of-the box way to
move this non-python dependency out of setup.py.
As setup.py is executed when building both sdists
and wheels, we need to libsemigroups to be
available in both stages.

An alternative option would be to modify
setuptools.build_meta and write custom build_sdist
and build_wheel functions (see PEP 517), but this
really didn't seem worth it.

Author: Joseph-Edwards

.github/workflows/wheels.yml

@@ -27,6 +27,8 @@ jobs:
       - uses: actions/setup-python@v5
       - name: Install cibuildwheel
         run: python -m pip install cibuildwheel==3.0.1
+      - name: Install libsemigroups
+        run: etc/install-libsemigroups.sh
       - name: Build wheels
         run: python -m cibuildwheel --output-dir wheelhouse
       - uses: actions/upload-artifact@v4
@@ -40,6 +42,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
+      - name: Install libsemigroups
+        run: etc/install-libsemigroups.sh
       - name: Build SDist
         run: pipx run build --sdist
       - uses: actions/upload-artifact@v4

etc/install-libsemigroups.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# If a command fails, exit this script with an error code
+set -e
+set -o pipefail
+
+VERSION=$(python etc/libsemigroups_version.py)
+curl -L -O https://github.com/libsemigroups/libsemigroups/releases/download/v$VERSION/libsemigroups-$VERSION.tar.gz
+tar -xf libsemigroups-$VERSION.tar.gz
+rm -f libsemigroups-$VERSION.tar.gz
+cd libsemigroups-$VERSION
+./configure --disable-hpcombi
+make -j4 && sudo make install

pyproject.toml

@@ -102,15 +102,8 @@ dev = [
 [tool.cibuildwheel]
 test-groups = ["test"]
 test-command = "pytest {project}/tests"
-build-frontend = "build[uv]"
+build-frontend = "build"
 build-verbosity = 1
-before-all = ["VERSION=$(python etc/libsemigroups_version.py)",
-    "curl -L -O https://github.com/libsemigroups/libsemigroups/releases/download/v$VERSION/libsemigroups-$VERSION.tar.gz",
-    "tar -xf libsemigroups-$VERSION.tar.gz",
-    "rm -f libsemigroups-$VERSION.tar.gz",
-    "cd libsemigroups-$VERSION",
-    "./configure --disable-hpcombi",
-    "make -j14 && make install"]
 
 [tool.cibuildwheel.linux]
 environment= "LD_LIBRARY_PATH='$LD_LIBRARY_PATH:/usr/lib:/usr/local/lib' PKG_CONFIG_PATH='$PKG_CONFIG_PATH:/usr/lib/pkgconfig:/usr/local/lib/pkgconfig'"