add more info when calcurve not found

Change-Id: I10bb7e46dad8b023a92599aeafdc75e1fdbf8de2

frappy_psi/calcurve.py

@@ -279,7 +279,8 @@ class CalCurve(HasOptions):
             if dot:
                 self.calibname = head
             kind = None
-            pathlist = [Path(p.strip()) for p in os.environ.get('FRAPPY_CALIB_PATH', '').split(':')]
+            rawpath = os.environ.get('FRAPPY_CALIB_PATH', '')
+            pathlist = [Path(p.strip()) for p in rawpath.split(':')]
             pathlist.append(Path(dirname(__file__)) / 'calcurves')
             for path in pathlist:
                 # first try without adding kind
@@ -301,7 +302,7 @@ class CalCurve(HasOptions):
                     continue
                 break
             else:
-                raise FileNotFoundError(calibname)
+                raise FileNotFoundError(f'{calibname} in {[str(p) for p in pathlist]}')
             sensopt = iter(sensopt)
             for opt in sensopt:
                 key, _, value = opt.lower().partition('=')