Handle SCIP on windows bug in solver_capabilities.py

Author: FBumann

dev-scripts/SOLVER_CAPABILITIES_PLAN.md

@@ -282,9 +282,6 @@ Replace:
 # Before (model.py:1199)
 if solver_name in NO_SOLUTION_FILE_SOLVERS:
 
-# Before (model.py:1211)
-if solver_name not in quadratic_solvers:
-
 # Before (model.py:1234)
 if solver_name in ["glpk", "cbc"]:
 
@@ -296,11 +293,12 @@ With:
 ```python
 # After
 if solver_supports(solver_name, SolverFeature.SOLUTION_FILE_NOT_NEEDED):
-if not solver_supports(solver_name, SolverFeature.QUADRATIC_OBJECTIVE):
 if not solver_supports(solver_name, SolverFeature.LP_FILE_NAMES):
 if solver_supports(solver_name, SolverFeature.IIS_COMPUTATION):
 ```
 
+**Note**: The quadratic solver check (`solver_name not in quadratic_solvers`) is NOT migrated to use `solver_supports()`. This is because tests may modify the `quadratic_solvers` list at runtime to exclude solvers with platform-specific bugs (e.g., SCIP on Windows). The list-based approach allows this runtime modification.
+
 ### Step 4: Update `variables.py`
 
 Replace:
@@ -330,7 +328,7 @@ Note: `io.py` doesn't need changes - the check at line 508 (`"highs" not in avai
 |------|---------|
 | `linopy/solver_capabilities.py` | **NEW** - Core registry module (~150 lines) |
 | `linopy/solvers.py` | Import registry, generate compat lists (~10 lines changed) |
-| `linopy/model.py` | Replace 4 hardcoded checks |
+| `linopy/model.py` | Replace 3 hardcoded checks (quadratic check kept as-is) |
 | `linopy/variables.py` | Replace 1 hardcoded check |
 | `linopy/__init__.py` | Export `SolverFeature`, `solver_supports` (optional) |
 

linopy/solver_capabilities.py

@@ -7,6 +7,7 @@
 
 from __future__ import annotations
 
+import platform
 from dataclasses import dataclass
 from enum import Enum, auto
 from typing import TYPE_CHECKING
@@ -112,10 +113,17 @@ def supports(self, feature: SolverFeature) -> bool:
         display_name="SCIP",
         features=frozenset(
             {
+                SolverFeature.LP_FILE_NAMES,
+                SolverFeature.SOLUTION_FILE_NOT_NEEDED,
+            }
+            if platform.system() == "Windows"
+            else {
                 SolverFeature.QUADRATIC_OBJECTIVE,
                 SolverFeature.LP_FILE_NAMES,
                 SolverFeature.SOLUTION_FILE_NOT_NEEDED,
             }
+            # SCIP has a bug with quadratic models on Windows, see:
+            # https://github.com/PyPSA/linopy/actions/runs/7615240686/job/20739454099?pr=78
         ),
     ),
     "mosek": SolverInfo(

test/test_optimization.py

@@ -9,7 +9,6 @@
 
 import itertools
 import logging
-import platform
 from typing import Any
 
 import numpy as np
@@ -47,11 +46,9 @@
     params.append(("mosek", "lp", True))
 
 
-feasible_quadratic_solvers: list[str] = quadratic_solvers
-# There seems to be a bug in scipopt with quadratic models on windows, see
-# https://github.com/PyPSA/linopy/actions/runs/7615240686/job/20739454099?pr=78
-if platform.system() == "Windows" and "scip" in feasible_quadratic_solvers:
-    feasible_quadratic_solvers.remove("scip")
+# Note: Platform-specific solver bugs (e.g., SCIP quadratic on Windows) are now
+# handled in linopy/solver_capabilities.py by adjusting the registry at import time.
+feasible_quadratic_solvers: list[str] = list(quadratic_solvers)
 
 
 def test_print_solvers(capsys: Any) -> None: