Fix build for Fedora 40 and 42

Author: tobiasdiez

.devcontainer/portability-fedora-42/devcontainer.json

@@ -0,0 +1,20 @@
+// See https://aka.ms/devcontainer.json for format details.
+{
+    "name": "fedora-42",
+    "image": "fedora:42",
+    "onCreateCommand": ".devcontainer/onCreate-meson.sh || true",
+    "features": {
+        "ghcr.io/devcontainers/features/git": {},
+        "ghcr.io/devcontainers/features/python:1": {},
+        "../uv": {
+			"version": "latest"
+		}
+    },
+    "customizations": {
+        "vscode": {
+            "extensions": [
+                "ms-python.python"
+            ]
+        }
+    }
+}

.github/workflows/ci.yml

@@ -11,6 +11,7 @@ on:
 
 jobs:
   build:
+    name: Build and Test
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -41,6 +42,11 @@ jobs:
 
       - name: Install dependencies
         run: |
+          # Install dnf5
+          if [ "${{ matrix.container }}" = "fedora:40" ] && ! rpm -q dnf5 >/dev/null; then
+              rpm-ostree install dnf5 dnf5-plugins
+          fi
+
           SYSTEM=$(build/bin/sage-guess-package-system)
           if [ "$SYSTEM" = "fedora" ]; then
               # Need to use --setopt=tsflags="" to avoid errors with gphelp

src/sage/graphs/graph_decompositions/meson.build

@@ -5,7 +5,7 @@ else
   tdlib = disabler()
 endif
 # Cannot be found via pkg-config
-rw = cc.find_library('rw')
+rw = cc.find_library('rw', required: false, disabler: true)
 
 py.install_sources(
   '__init__.py',