ci: improvements to igraph build

.github/workflows/build-cmake.yml

@@ -3,25 +3,28 @@ name: Build and test
 on: [push, pull_request]
 
 env:
-  ASAN_OPTIONS: detect_stack_use_after_return=1:color=always
+  ASAN_OPTIONS: detect_stack_use_after_return=1:detect_leaks=1:color=always
   UBSAN_OPTIONS: print_stacktrace=1:color=always
-  OMP_NUM_THREADS: 1
+  CCACHE_DIR: ${{ github.workspace }}/ccache
+  CCACHE_MAXSIZE: 128M
+  IGRAPH_VERSION: 0.10.13
 
 jobs:
   build:
     runs-on: ubuntu-24.04
 
     steps:
       - name: Install igraph dependencies
-        run: sudo apt-get install libglpk-dev libarpack2-dev
+        run: sudo apt-get install ccache libglpk-dev libarpack2-dev
 
       - name: Build igraph
         run: |
-          wget https://github.com/igraph/igraph/releases/download/0.10.13/igraph-0.10.13.tar.gz
-          tar xfz igraph-0.10.13.tar.gz
-          cd igraph-0.10.13
+          cd $GITHUB_WORKSPACE
+          wget https://github.com/igraph/igraph/releases/download/$IGRAPH_VERSION/igraph-$IGRAPH_VERSION.tar.gz
+          tar xfz igraph-$IGRAPH_VERSION.tar.gz
+          cd igraph-$IGRAPH_VERSION
           mkdir build && cd build
-          cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/local
+          cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/local -DBUILD_SHARED_LIBS=ON -DUSE_SANITIZER=Address -DCMAKE_BUILD_TYPE=Debug
           cmake --build . --parallel
           cmake --install .