Bugfix in restart throwing errors

Author: lindonroberts

dfols/__init__.py

@@ -39,7 +39,7 @@
 from __future__ import absolute_import, division, print_function, unicode_literals
 
 # DFO-LS version
-__version__ = '1.6.4'
+__version__ = '1.6.5'
 
 # Main solver & exit flags
 from .solver import *

dfols/controller.py

@@ -609,7 +609,13 @@ def geometry_step(self, knew, adelt, number_of_samples, params, throw_error_on_n
             else:
                 # Solve problem: bounds are sl <= xnew <= su, and ||xnew-xopt|| <= adelt
                 xnew = trsbox_geometry(self.model.xopt(), c, g, np.minimum(self.model.sl, 0.0), np.maximum(self.model.su, 0.0), adelt)
-        except LA.LinAlgError:
+        except LA.LinAlgError as e:
+            # This could come from throw_error_on_nans, in which case we actually want to throw properly
+            if throw_error_on_nans and "NaN encountered in objective evaluations" in str(e):
+                # Re-raise
+                raise np.linalg.LinAlgError(str(e))
+
+            # Otherwise, handle silently
             exit_info = ExitInformation(EXIT_LINALG_ERROR, "Singular matrix encountered in geometry step")
             return exit_info  # didn't fix geometry - return & quit
 

dfols/model.py

@@ -431,6 +431,8 @@ def lagrange_gradient(self, k=None, factorise_first=True, throw_error_on_nans=Fa
             if np.any(np.isnan(self.fval_v[fval_row_idx, :])):  # check objective values
                 if self.do_logging:
                     module_logger.warning("model.lagrange_gradient: NaNs encountered in objective evaluations, raising error")
+                # WARNING: Do not change this error message without checking controller.geometry_step
+                # error handling/string matching
                 raise np.linalg.LinAlgError("NaN encountered in objective evaluations during Lagrange polynomial construction")
 
         soln = self.solve_geom_system(rhs)

docs/history.rst

@@ -107,3 +107,7 @@ Version 1.6.4 (23 Mar 2026)
 -------------------------
 * Add new parameter :code:`restarts.throw_error_on_nans` to customize handling of NaN objective values during restarts
 
+Version 1.6.5 (23 Mar 2026)
+-------------------------
+* Bugfix in handling of :code:`restarts.throw_error_on_nans` from v1.6.4
+