From c2052c11692d223fb5553af1d16f17321ddb5a9d Mon Sep 17 00:00:00 2001
From: Jeff Epler <jepler@gmail.com>
Date: Mon, 9 Nov 2020 07:33:41 -0600
Subject: [PATCH] Give clear error about bit length on import

---
 jepler_udecimal/__init__.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/jepler_udecimal/__init__.py b/jepler_udecimal/__init__.py
index df23f5c..dad4f32 100644
--- a/jepler_udecimal/__init__.py
+++ b/jepler_udecimal/__init__.py
@@ -160,6 +160,11 @@ except NameError:
 
 if sys.implementation.name == "circuitpython":
 
+    if not hasattr(int, "bit_length"):
+        raise ImportError(
+            "jepler_udecimal requires int.bit_length.  Use CircuitPython 6.0.0-rc.1 or newer."
+        )
+
     def _as_integer_ratio(f):
         m, e = _math.frexp(f)
         m = round(m * (1 << 53))