Merge pull request #165 from ProvideQ/fix/gams-scip

Changed GAMS MIP solver to SCIP and improved test output in CI pipeline.

Author: koalamitice

.github/workflows/ci-cd.yml

@@ -40,13 +40,15 @@ jobs:
             venv-${{ runner.os }}-
 
       - name: Install solver dependencies
+        env:
+          GAMSPY_LICENSE: ${{ secrets.GAMSPY_LICENSE }}
         run: ./scripts/ci-setup-solvers.sh
 
       - name: Run checks
         shell: bash # required for the source command
         run: | # change to "./gradlew check --info" for more debugging output.
           source /opt/conda/bin/activate gams
-          ./gradlew check --info
+          ./gradlew check
 
       - name: Archive test reports
         if: always()
@@ -81,4 +83,4 @@ jobs:
           command_timeout: 60m
           script: |
             echo "Deploying ${{ github.event.repository.name }} to '${{ github.ref_name }}' environment"
-            sh /root/ProvideQ/${{ github.event.repository.name }}/deploy.sh ${{ github.ref_name }}
+            sh /root/ProvideQ/${{ github.event.repository.name }}/deploy.sh ${{ github.ref_name }}

.gitignore

@@ -1,6 +1,7 @@
 HELP.md
 *.DS_Store
 .gradle
+.gamspy_license
 build/
 !gradle/wrapper/gradle-wrapper.jar
 !**/src/main/**/build/

build.gradle

@@ -37,6 +37,12 @@ jar {
 // inject JUnit into test task
 tasks.named('test') {
     useJUnitPlatform()
+
+    // Show test output (System.out.println, etc)
+    testLogging {
+        showStandardStreams = true
+        events "passed", "skipped", "failed"
+    }
 }
 
 tasks.withType(JavaCompile).configureEach {

scripts/install-python-dependencies.py

@@ -14,6 +14,23 @@
     os.path.join(root_dir, 'solvers'),
 ]
 
+def get_gamspy_license():
+    # 1. Environment variable (GitHub Actions)
+    license_key = os.environ.get("GAMSPY_LICENSE")
+    if license_key:
+        return license_key.strip()
+
+    # 2. Local file (ignored by git)
+    license_file = os.path.join(root_dir, ".gamspy_license")
+    if os.path.exists(license_file):
+        with open(license_file) as f:
+            return f.read().strip()
+
+    raise RuntimeError(
+        "No GAMSPY license found. "
+        "Set the GAMSPY_LICENSE environment variable or create a .gamspy_license file."
+    )
+
 exitCode = 0
 for base_dir in base_dirs:
     for root, dirs, files in os.walk(base_dir):
@@ -24,25 +41,69 @@
             # Iterate over problem directory (knapsack, tsp, etc.)
             for solver_name in os.listdir(framework_dir):
                 solver_dir = os.path.join(framework_dir, solver_name)
+
                 # If folder filter is specified, only process matching folders
                 if folder_filter and folder_filter not in solver_dir:
                     continue
 
                 req_file = os.path.join(solver_dir, 'requirements.txt')
                 if os.path.exists(req_file):
                     venv_name = f"{os.path.basename(root)}_{framework_name}_{solver_name}"
-                    print(f"Setting up virtual environment '{venv_name}' for {solver_dir}...")
+
+                    print(f"Setting up virtual environment '{venv_name}'")
                     try:
                         venv_path = os.path.join('venv', venv_name)
-                        subprocess.run(['python', '-m', 'venv', venv_path], check=True)
+                        subprocess.run(['python', '-m', 'venv', venv_path], check=True, capture_output=True)
                         if platform.system() == 'Windows':
                             pip_executable = os.path.join(venv_path, 'Scripts', 'pip.exe')
+                            python_executable = os.path.join(venv_path, 'Scripts', 'python.exe')
                         else:
                             pip_executable = os.path.join(venv_path, 'bin', 'pip')
-                        subprocess.run([pip_executable, 'install', '-r', req_file], check=True)
+                            python_executable = os.path.join(venv_path, 'bin', 'python')
+
+                        # install dependencies from requirements.txt
+                        subprocess.run([pip_executable, 'install', '-r', req_file], check=True, capture_output=True)
+
+                        # install GAMSPy license if this is a GAMS environment
+                        if "gams" in venv_name.lower():
+                            license_key = get_gamspy_license()
+
+                            print("Installing GAMSPy license and scip solver ...")
+                            subprocess.run(
+                                [
+                                    python_executable,
+                                    "-m",
+                                    "gamspy",
+                                    "install",
+                                    "license",
+                                    license_key,
+                                ],
+                                check=True,
+                                capture_output=True,
+                            )
+
+                            subprocess.run(
+                                [
+                                    python_executable,
+                                    "-m",
+                                    "gamspy",
+                                    "install",
+                                    "solver",
+                                    "scip"
+                                ],
+                                check=True,
+                                capture_output=True,
+                            )
+
                     except subprocess.CalledProcessError as e:
-                        print(f"Error setting up virtual environment for {solver_dir}: {e}")
+                        print(f"Error setting up virtual environment '{venv_name}' for {solver_dir}:")
+                        if e.stdout:
+                            print("STDOUT:")
+                            print(e.stdout.decode() if isinstance(e.stdout, bytes) else e.stdout)
+                        if e.stderr:
+                            print("STDERR:")
+                            print(e.stderr.decode() if isinstance(e.stderr, bytes) else e.stderr)
                         exitCode = 1
 
 # let pipeline fail if there was an error in the venv setup.
-exit(exitCode)
+exit(exitCode)

solvers/gams/python/requirements.txt

@@ -1,3 +1,4 @@
-# This file describes the python package requirements for all GAMS solvers.
-# We only build one venv for all of GAMS, not for every GAMS solver.
+# This file contains of the python dependencies required in the .gms files
+# GamsPy solvers are handles extra.
 networkx
+gamspy == 1.23.1

solvers/gams/qubo/solver_lp_qubo.py

@@ -71,7 +71,8 @@ def parse_lp_to_df(filepath="unsplittable_model.lp"):
 )
 
 print("Solving model natively...")
-qubo_model.solve(solver="CPLEX", output=sys.stdout, options=gp.Options(time_limit=60))
+qubo_model.solve(solver="SCIP", solver_options={"lp/solver": '"highs"'},
+                 output=sys.stdout, options=gp.Options(time_limit=60))
 
 print(f"\n--- Solver Status: {qubo_model.status} ---")
 print(f"--- Objective Value: {qubo_model.objective_value} ---")
@@ -88,4 +89,4 @@ def parse_lp_to_df(filepath="unsplittable_model.lp"):
 with open(output_path, "w") as f:
     json.dump(solution_dict, f, indent=4)
 
-print(f"--- Extracted {len(solution_dict)} active variables to {output_path} ---")
+print(f"--- Extracted {len(solution_dict)} active variables to {output_path} ---")

solvers/gams/unsplittable-mcf/solver_classical.py

@@ -26,4 +26,4 @@
 model.build_equations_and_model()
 
 print("\n--- Solving Classical MIP with CPLEX ---")
-model.solve_classical(solver="CPLEX", output_html=output_path)
+model.solve_classical(solver="SCIP", output_html=output_path)

src/main/java/edu/kit/provideq/toolbox/qubo/solvers/GamsQuboSolver.java

@@ -33,13 +33,13 @@ public GamsQuboSolver(
 
   @Override
   public String getName() {
-    return "(GAMS) CPLEX Solver for QUBOs";
+    return "(GAMS) SCIP Solver for QUBOs";
   }
 
   @Override
   public String getDescription() {
     return "Solves QUBO problems by transforming it into a MIP,"
-        + "which is then solved with CPLEX. Implementation is done in GAMS";
+        + "which is then solved with SCIP. Implementation is done in GAMS";
   }
 
   @Override

src/main/java/edu/kit/provideq/toolbox/unsplittablemcf/solvers/GamsUnsplittableMcfClassicalSolver.java

@@ -34,12 +34,12 @@ public GamsUnsplittableMcfClassicalSolver(
 
   @Override
   public String getName() {
-    return "(GAMS) CPLEX Classical MCF Solver";
+    return "(GAMS) SCIP Classical MCF Solver";
   }
 
   @Override
   public String getDescription() {
-    return "Solves the Unsplittable Multi Commodity Flow problem using GAMSPy with CPLEX. "
+    return "Solves the Unsplittable Multi Commodity Flow problem using GAMSPy and SCIP. "
         + "Builds a time-expanded network model and finds optimal flow routes minimizing "
         + "delay and slack penalties.";
   }

src/test/java/edu/kit/provideq/toolbox/api/ApiTestHelper.java

@@ -209,6 +209,7 @@ public static <InputT, ResultT> ProblemDto<InputT, ResultT> trySolveFor(
     // print error output if something went wrong
     if (problemDto.getState() != ProblemState.SOLVED
         || problemDto.getSolution().getStatus() != SolutionStatus.SOLVED) {
+      System.out.println("Testcase failed. Printing debugging info:");
       System.out.println(builder);
     }