@@ -28,6 +28,8 @@ def set_runtime(runtime: Union[clr_loader.Runtime, str], **params: str) -> None:
2828
2929
3030def get_runtime_info ()-> Optional [clr_loader .RuntimeInfo ]:
31+ """Retrieve information on the configured runtime"""
32+
3133if _RUNTIME is None :
3234return None
3335else :
@@ -52,22 +54,39 @@ def _get_params_from_env(prefix: str) -> Dict[str, str]:
5254def _create_runtime_from_spec (
5355spec :str ,params :Optional [Dict [str ,Any ]]= None
5456)-> clr_loader .Runtime :
57+ was_default = False
5558if spec == "default" :
59+ was_default = True
5660if sys .platform == "win32" :
5761spec = "netfx"
5862else :
5963spec = "mono"
6064
6165params = params or _get_params_from_env (spec )
6266
63- if spec == "netfx" :
64- return clr_loader .get_netfx (** params )
65- elif spec == "mono" :
66- return clr_loader .get_mono (** params )
67- elif spec == "coreclr" :
68- return clr_loader .get_coreclr (** params )
69- else :
70- raise RuntimeError (f"Invalid runtime name: '{ spec } )
67+ try :
68+ if spec == "netfx" :
69+ return clr_loader .get_netfx (** params )
70+ elif spec == "mono" :
71+ return clr_loader .get_mono (** params )
72+ elif spec == "coreclr" :
73+ return clr_loader .get_coreclr (** params )
74+ else :
75+ raise RuntimeError (f"Invalid runtime name: '{ spec } )
76+ except Exception as exc :
77+ if was_default :
78+ raise RuntimeError (
79+ f"""Failed to create a default .NET runtime, which would
80+ have been "{ spec }
81+ compatible runtime or configure it explicitly via
82+ `set_runtime` or the `PYTHONNET_*` environment variables
83+ (see set_runtime_from_env)."""
84+ )from exc
85+ else :
86+ raise RuntimeError (
87+ f"""Failed to create a .NET runtime ({ spec }
88+ parameters{ params }
89+ )from exc
7190
7291
7392def set_runtime_from_env ()-> None :
@@ -92,9 +111,7 @@ def set_runtime_from_env() -> None:
92111set_runtime (runtime )
93112
94113
95- def load (
96- runtime :Union [clr_loader .Runtime ,str ,None ]= None ,** params :str
97- )-> None :
114+ def load (runtime :Union [clr_loader .Runtime ,str ,None ]= None ,** params :str )-> None :
98115"""Load Python.NET in the specified runtime
99116
100117 The same parameters as for `set_runtime` can be used. By default,