build: fix swig install under centos/manylinux

.github/workflows/wheels.yml

@@ -17,7 +17,7 @@ jobs:
       matrix:
         os: [ubuntu-22.04, windows-2019, macos-14]
     env:
-      CIBW_BEFORE_ALL_LINUX: yum install -y swig || apk add swig
+      CIBW_BEFORE_ALL_LINUX: ./tools/install_swig.sh
       CIBW_BEFORE_ALL_MACOS: brew install gnu-sed swig automake libtool
       CIBW_BEFORE_ALL_WINDOWS: choco install swig --version=3.0.12 --no-progress --allow-downgrade -y
       CIBW_BEFORE_BUILD_WINDOWS: .\tools\msvc\swig.bat

tools/install_swig.sh

@@ -0,0 +1,49 @@
+#! /usr/bin/env bash
+set -e
+
+if [ $(command -v swig) ]; then
+    # Already installed
+    exit 0
+fi
+
+if [ $(command -v apt) ]; then
+    # Debian/Ubuntu
+    apt install swig
+    exit 0
+fi
+
+if [ -d /etc/yum.repos.d ]; then
+    # Redhat/Fedora
+    if grep -- mirror.centos.org /etc/yum.repos.d/*.repo >/dev/null 2>&1; then
+        # mirror.centos.org has been nuked. Attempt to update the repo spec
+        # for older manylinux docker builds
+        sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/*.repo
+        sed -i s/^#.*baseurl=http/baseurl=http/g /etc/yum.repos.d/*.repo
+        sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/*.repo
+    fi
+    yum install -y swig
+    exit 0
+fi
+
+if [ $(command -v brew) ]; then
+    # MacOS
+    brew install swig
+    exit 0
+fi
+
+if [ $(command -v apk) ]; then
+    # Alpine
+    apk add swig
+    exit 0
+fi
+
+# Unknown - install from source
+SWIG_URL='https://downloads.sourceforge.net/project/swig/swig/swig-3.0.12/swig-3.0.12.tar.gz?use_mirror=autoselect'
+curl -sSL ${SWIG_URL} | tar xz
+pushd swig-3.0.12 >/dev/null
+./configure
+make -j4
+make install
+popd >/dev/null
+rm -rf swig-3.0.12
+exit 0