Added an install check action, fixed the CMake variables.

.github/workflows/check-install.yaml

@@ -0,0 +1,56 @@
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+name: Check CMake install
+
+jobs:
+  install:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Get latest CMake
+      uses: lukka/get-cmake@latest
+
+    - name: Cache installed igraph
+      id: cache-igraph
+      uses: actions/cache@v4
+      with:
+        path: _deps
+        key: libigraph
+
+    - name: Make and install igraph
+      if: ${{ steps.cache-igraph.outputs.cache-hit != 'true' }}
+      run: |
+        version=0.10.13
+        path=$(pwd)
+        wget https://github.com/igraph/igraph/releases/download/${version}/igraph-${version}.tar.gz
+        tar -xf igraph-${version}.tar.gz
+        cd igraph-${version}
+        mkdir build && cd build
+        cmake .. -DCMAKE_INSTALL_PREFIX=${path}/_deps
+        cmake --build .
+        sudo cmake --install .
+
+    - name: Configure the build
+      run: cmake -S . -B build -DSCRAN_GRAPH_CLUSTER_TESTS=OFF -DCMAKE_PREFIX_PATH=_deps
+
+    - name: Install the library
+      run: sudo cmake --install build
+
+    - name: Test downstream usage
+      run: |
+        mkdir _downstream
+        touch _downstream/source.cpp
+        cat << EOF > _downstream/CMakeLists.txt
+        cmake_minimum_required(VERSION 3.24)
+        project(test_install)
+        add_executable(whee source.cpp)
+        find_package(libscran_scran_graph_cluster)
+        target_link_libraries(whee libscran::scran_graph_cluster)
+        EOF
+        cd _downstream && cmake -S . -B build

CMakeLists.txt

@@ -15,16 +15,16 @@ target_include_directories(scran_graph_cluster INTERFACE
 target_compile_features(scran_graph_cluster INTERFACE cxx_std_17)
 
 # Dependencies
-option(SCRAN_MARKERS_FETCH_EXTERN "Automatically fetch scran_graph_cluster's external dependencies (except for igraph)." ON)
-option(SCRAN_MARKERS_FETCH_EXTERN_IGRAPH "Automatically fetch scran_graph_cluster's external igraph dependency." OFF)
+option(SCRAN_GRAPH_CLUSTER_FETCH_EXTERN "Automatically fetch scran_graph_cluster's external dependencies (except for igraph)." ON)
+option(SCRAN_GRAPH_CLUSTER_FETCH_EXTERN_IGRAPH "Automatically fetch scran_graph_cluster's external igraph dependency." OFF)
 
-if (NOT SCRAN_MARKERS_FETCH_EXTERN_IGRAPH)
+if (NOT SCRAN_GRAPH_CLUSTER_FETCH_EXTERN_IGRAPH)
     # igraph needs compilation so we just try to get it from the system by
     # default, rather than pulling it down and building the whole thing.
     find_package(igraph 0.10.0 CONFIG REQUIRED)
 endif()
 
-if(SCRAN_MARKERS_FETCH_EXTERN)
+if(SCRAN_GRAPH_CLUSTER_FETCH_EXTERN)
     add_subdirectory(extern)
 else()
     find_package(ltla_raiigraph 1.0.0 CONFIG REQUIRED)
@@ -35,12 +35,12 @@ target_link_libraries(scran_graph_cluster INTERFACE igraph::igraph ltla::raiigra
 
 # Tests
 if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
-    option(SCRAN_MARKERS_TESTS "Build scran_graph_cluster's test suite." ON)
+    option(SCRAN_GRAPH_CLUSTER_TESTS "Build scran_graph_cluster's test suite." ON)
 else()
-    option(SCRAN_MARKERS_TESTS "Build scran_graph_cluster's test suite." OFF)
+    option(SCRAN_GRAPH_CLUSTER_TESTS "Build scran_graph_cluster's test suite." OFF)
 endif()
 
-if(SCRAN_MARKERS_TESTS)
+if(SCRAN_GRAPH_CLUSTER_TESTS)
     include(CTest)
     if(BUILD_TESTING)
         add_subdirectory(tests)