Trying xfail PHE tests only on Windows

idaes/models_extra/column_models/tests/test_plate_heat_exchanger.py

@@ -14,15 +14,18 @@
 Tests for Plate Heat Exchnager  unit model.
 Author: Akula Paul
 """
-
+import sys
 import pytest
+
 from pyomo.environ import (
     check_optimal_termination,
     ConcreteModel,
     Param,
     units as pyunits,
     value,
 )
+from pyomo.util.check_units import assert_units_consistent, assert_units_equivalent
+
 from idaes.core import FlowsheetBlock
 from idaes.models_extra.column_models.plate_heat_exchanger import (
     PlateHeatExchanger as PHE,
@@ -37,7 +40,6 @@
 from idaes.core.util.model_statistics import degrees_of_freedom
 from idaes.core.util.testing import initialization_tester
 from idaes.core.solvers import get_solver
-from pyomo.util.check_units import assert_units_consistent, assert_units_equivalent
 
 
 # -----------------------------------------------------------------------------
@@ -66,8 +68,10 @@ def test_config():
 
 
 workaround_for_1294 = pytest.mark.xfail(
+    sys.platform
+    == "win32",  # the failures only occur for Windows on GHA with Python <3.12
     reason="These tests fail with Pyomo 6.7.0. See IDAES/idaes-pse#1294 for details",
-    strict=False,  # the failures only occur for certain platforms, e.g. Windows on GHA
+    strict=False,
 )