Add test

pvlib/irradiance.py

@@ -1513,11 +1513,14 @@ def poa_error(ghi):
                         full_output=True,
                         disp=False,
                         )
-    except ValueError:
-        # this occurs when poa_error has the same sign at both end points
-        ghi = np.nan
-        conv = False
-        niter = -1
+    except ValueError as e:
+        # this may occur because poa_error has the same sign at both end points
+        if "f(a) and f(b) must have different signs" in e.args:
+            ghi = np.nan
+            conv = False
+            niter = -1
+        else:
+            raise e
     else:
         ghi = result[0]
         conv = result[1].converged

pvlib/tests/test_irradiance.py

@@ -1,6 +1,7 @@
 import datetime
 from collections import OrderedDict
 import warnings
+import re
 
 import numpy as np
 from numpy import array, nan
@@ -825,6 +826,16 @@ def test_ghi_from_poa_driesse():
     expected = [0, -1, 0]
     assert_allclose(expected, niter)
 
+    # test xtol propagation by producing an exception
+    poa_global = pd.Series([20, 300, 1000], index=times)
+    xtol = -3.14159  # negative value raises exception in scipy.optimize.bisect
+    with pytest.raises(
+        ValueError,
+        match=re.escape("xtol too small (%g <= 0)" % xtol)):
+        output = irradiance.ghi_from_poa_driesse_2023(
+            surface_tilt, surface_azimuth, zenith, azimuth,
+            poa_global, dni_extra=1366.1, xtol=xtol)
+
 
 def test_gti_dirint():
     times = pd.DatetimeIndex(