Improving fix for ASL issue

idaes/core/util/model_diagnostics.py

@@ -18,7 +18,6 @@
 __author__ = "Alexander Dowling, Douglas Allan, Andrew Lee, Robby Parker, Ben Knueven"
 
 from operator import itemgetter
-import os
 import sys
 from inspect import signature
 from math import log, isclose, inf, isfinite
@@ -77,7 +76,6 @@
 from pyomo.common.deprecation import deprecation_warning
 from pyomo.common.errors import PyomoException
 from pyomo.common.tempfiles import TempfileManager
-from pyomo.common.fileutils import find_library
 
 from idaes.core.util.model_statistics import (
     activated_blocks_set,
@@ -441,23 +439,27 @@ def __init__(self, model: _BlockData, **kwargs):
         self._model = model
         self.config = CONFIG(kwargs)
 
-        # There appears to be a bug in the ASL which causes terminal failures
-        # if you try to create multiple ASL structs with different external
-        # functions in the same process. This causes pytest to crash during testing.
-        # To avoid this, register all known external functions before we call
-        # PyNumero.
-        ext_funcs = ["cubic_roots", "general_helmholtz_external", "functions"]
-        library_set = set()
-        libraries = []
-
-        for f in ext_funcs:
-            library = find_library(f)
-            if library not in library_set:
-                library_set.add(library)
-                libraries.append(library)
-
-        lib_str = "\n".join(libraries)
-        os.environ["AMPLFUNC"] = lib_str
+        # # There appears to be a bug in the ASL which causes terminal failures
+        # # if you try to create multiple ASL structs with different external
+        # # functions in the same process. This causes pytest to crash during testing.
+        # # To avoid this, register all known external functions before we call
+        # # PyNumero.
+        # ext_funcs = ["cubic_roots", "general_helmholtz_external", "functions"]
+        # library_set = set()
+        # libraries = []
+        #
+        # for f in ext_funcs:
+        #     library = find_library(f)
+        #     if library not in library_set:
+        #         library_set.add(library)
+        #         libraries.append(library)
+        #
+        # if "AMPLFUNC" in os.environ:
+        #     env_str = "\n".join([os.environ["AMPLFUNC"], *libraries])
+        # else:
+        #     env_str = "\n".join(libraries)
+        #
+        # os.environ["AMPLFUNC"] = env_str
 
     @property
     def model(self):
@@ -1430,9 +1432,17 @@ def report_numerical_issues(self, stream=None):
         cautions = self._collect_numerical_cautions(jac=jac, nlp=nlp)
 
         stats = []
-        stats.append(
-            f"Jacobian Condition Number: {jacobian_cond(jac=jac, scaled=False):.3E}"
-        )
+        try:
+            stats.append(
+                f"Jacobian Condition Number: {jacobian_cond(jac=jac, scaled=False):.3E}"
+            )
+        except RuntimeError as err:
+            if "Factor is exactly singular" in str(err):
+                _log.info(err)
+                stats.append(f"Jacobian Condition Number: Undefined (Exactly Singular)")
+            else:
+                raise
+
         _write_report_section(
             stream=stream, lines_list=stats, title="Model Statistics", header="="
         )

idaes/core/util/scaling.py

@@ -28,6 +28,7 @@
 __author__ = "John Eslick, Tim Bartholomew, Robert Parker, Andrew Lee"
 
 import math
+import os
 import sys
 
 import scipy.sparse.linalg as spla
@@ -49,12 +50,36 @@
 from pyomo.core import expr as EXPR
 from pyomo.common.numeric_types import native_types
 from pyomo.core.base.units_container import _PyomoUnit
+from pyomo.common.fileutils import find_library
 
 import idaes.logger as idaeslog
 
 _log = idaeslog.getLogger(__name__)
 
 
+# There appears to be a bug in the ASL which causes terminal failures
+# if you try to create multiple ASL structs with different external
+# functions in the same process. This causes pytest to crash during testing.
+# To avoid this, register all known external functions before we call
+# PyNumero.
+ext_funcs = ["cubic_roots", "general_helmholtz_external", "functions"]
+library_set = set()
+libraries = []
+
+for f in ext_funcs:
+    library = find_library(f)
+    if library not in library_set:
+        library_set.add(library)
+        libraries.append(library)
+
+if "AMPLFUNC" in os.environ:
+    env_str = "\n".join([os.environ["AMPLFUNC"], *libraries])
+else:
+    env_str = "\n".join(libraries)
+
+os.environ["AMPLFUNC"] = env_str
+
+
 def __none_left_mult(x, y):
     """PRIVATE FUNCTION, If x is None return None, else return x * y"""
     if x is not None:

idaes/core/util/tests/test_model_diagnostics.py

@@ -33,6 +33,7 @@
     acos,
     sqrt,
     Objective,
+    PositiveIntegers,
     Set,
     SolverFactory,
     Suffix,
@@ -1342,6 +1343,46 @@ def test_report_numerical_issues_ok(self):
         prepare_degeneracy_hunter()
         prepare_svd_toolbox()
 
+====================================================================================
+"""
+
+        assert stream.getvalue() == expected
+
+    @pytest.mark.component
+    def test_report_numerical_issues_exactly_singular(self):
+        m = ConcreteModel()
+        m.x = Var([1, 2], initialize=1.0)
+        m.eq = Constraint(PositiveIntegers)
+        m.eq[1] = m.x[1] * m.x[2] == 1.5
+        m.eq[2] = m.x[2] * m.x[1] == 1.5
+        m.obj = Objective(expr=m.x[1] ** 2 + 2 * m.x[2] ** 2)
+
+        dt = DiagnosticsToolbox(m)
+        dt.report_numerical_issues()
+
+        stream = StringIO()
+        dt.report_numerical_issues(stream)
+
+        expected = """====================================================================================
+Model Statistics
+
+    Jacobian Condition Number: Undefined (Exactly Singular)
+
+------------------------------------------------------------------------------------
+1 WARNINGS
+
+    WARNING: 2 Constraints with large residuals (>1.0E-05)
+
+------------------------------------------------------------------------------------
+0 Cautions
+
+    No cautions found!
+
+------------------------------------------------------------------------------------
+Suggested next steps:
+
+    display_constraints_with_large_residuals()
+
 ====================================================================================
 """