Try to find global SCIP installation

.github/workflows/build_and_test.yml

@@ -68,6 +68,31 @@ jobs:
           cargo t --features from-source create
           cargo t --features from-source --examples
 
+  linux-system-test:
+    runs-on: ubuntu-22.04
+    env:
+      SCIP_VERSION: 9.2.4
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Install SCIP from debian package
+        run: |
+          wget --quiet --no-check-certificate https://github.com/scipopt/scip/releases/download/v$(echo "${{ env.SCIP_VERSION }}" | tr -d '.')/SCIPOptSuite-${{ env.SCIP_VERSION }}-Linux-ubuntu22.deb
+          sudo apt-get update
+          sudo apt install -y ./SCIPOptSuite-${{ env.SCIP_VERSION }}-Linux-ubuntu22.deb
+
+      - name: Verify SCIP headers are in standard locations
+        run: |
+          echo "Checking for headers in standard locations..."
+          ls -la /usr/include/scip/ || echo "No headers in /usr/include/scip"
+          ls -la /usr/local/include/scip/ || echo "No headers in /usr/local/include/scip"
+
+      - name: Build and test (should find headers in system directories)
+        run: |
+          cargo b -vv
+          cargo t create
+          cargo t --examples
+
   linux-conda-test:
     runs-on: ubuntu-latest
     steps:

Cargo.toml

@@ -7,6 +7,9 @@ repository = "https://github.com/scipopt/scip-sys"
 license = "Apache-2.0"
 links = "scip"
 
+[package.metadata.docs.rs]
+features = ["bundled"]
+
 [features]
 bundled = ["ureq", "zip", "tempfile", "zip-extract"]
 from-source = ["ureq", "zip", "tempfile", "zip-extract", "cmake"]

build.rs

@@ -93,6 +93,40 @@ fn look_in_scipoptdir_and_conda_env() -> Option<bindgen::Builder> {
     return None;
 }
 
+fn try_system_include_paths() -> Option<bindgen::Builder> {
+    println!("cargo:warning=Searching for SCIP in standard system directories");
+
+    // Common system include paths
+    let search_paths = vec![
+        "/usr/include",
+        "/usr/local/include",
+        "/opt/local/include",           // MacPorts
+        "/opt/homebrew/include",         // Homebrew ARM Mac
+        "/usr/local/opt/scip/include",  // Homebrew Intel Mac
+    ];
+
+    for base_path in search_paths {
+        let base = PathBuf::from(base_path);
+        let scip_h = base.join("scip").join("scip.h");
+        let scipdefplugins_h = base.join("scip").join("scipdefplugins.h");
+
+        if scip_h.exists() && scipdefplugins_h.exists() {
+            println!("cargo:warning=Found SCIP headers in {}", base_path);
+
+            return Some(
+                bindgen::Builder::default()
+                    .header(scip_h.to_str().unwrap())
+                    .header(scipdefplugins_h.to_str().unwrap())
+                    .parse_callbacks(Box::new(bindgen::CargoCallbacks))
+                    .clang_arg(format!("-I{}", base_path))
+            );
+        }
+    }
+
+    println!("cargo:warning=Could not find SCIP headers in standard system directories");
+    None
+}
+
 fn main() -> Result<(), Box<dyn Error>> {
     let builder = if is_bundled_feature_enabled() {
         download_scip();
@@ -107,29 +141,20 @@ fn main() -> Result<(), Box<dyn Error>> {
         if builder.is_some() {
             builder.unwrap()
         } else {
-            println!("cargo:warning=SCIP was not found in SCIPOPTDIR or in Conda environemnt");
+            println!("cargo:warning=SCIP was not found in SCIPOPTDIR or in Conda environment");
             println!("cargo:warning=Looking for SCIP in system libraries");
 
-            let headers_dir_path = "headers/";
-            let headers_dir = PathBuf::from(headers_dir_path);
-            let scip_header_file = PathBuf::from(&headers_dir)
-                .join("scip")
-                .join("scip.h")
-                .to_str()
-                .unwrap()
-                .to_owned();
-            let scipdefplugins_header_file = PathBuf::from(&headers_dir)
-                .join("scip")
-                .join("scipdefplugins.h")
-                .to_str()
-                .unwrap()
-                .to_owned();
-
-            bindgen::Builder::default()
-                .header(scip_header_file)
-                .header(scipdefplugins_header_file)
-                .parse_callbacks(Box::new(bindgen::CargoCallbacks))
-                .clang_arg(format!("-I{}", headers_dir_path))
+            // Try common system include paths
+            try_system_include_paths().unwrap_or_else(|| {
+                panic!(
+                    "Could not find SCIP installation.\n\
+                    Please either:\n\
+                    - Set SCIPOPTDIR environment variable to point to your SCIP installation\n\
+                    - Install SCIP system-wide (headers in /usr/include or /usr/local/include)\n\
+                    - Use --features bundled to download and use a bundled version\n\
+                    - Use --features from-source to build SCIP from source"
+                )
+            })
         }
     };