Force DeprecationWarning's to be visible.

rasterio/__init__.py

@@ -12,8 +12,6 @@ except ImportError:  # pragma: no cover
         def emit(self, record):
             pass
 
-import affine
-
 from rasterio._base import (
     eval_window, window_shape, window_index, gdal_version)
 from rasterio.dtypes import (
@@ -164,12 +162,14 @@ def open(path, mode='r', driver=None, width=None, height=None,
         raise ValueError("The 'affine' and 'transform' arguments are exclusive")
     elif 'affine' in kwargs:
         transform = kwargs.pop('affine')
-        warnings.warn(
-            "The affine kwarg is deprecated as of 1.0 and only exists to ease "
-            "the transition.  Please switch to the transform kwarg.  See "
-            "https://github.com/mapbox/rasterio/issues/86 for details.",
-            RuntimeWarning,
-            stacklevel=2)
+        with warnings.catch_warnings():
+            warnings.simplefilter('always')
+            warnings.warn(
+                "The affine kwarg is deprecated as of 1.0 and only exists to "
+                "ease the transition.  Please switch to the transform kwarg.  "
+                "See https://github.com/mapbox/rasterio/issues/86 for details.",
+                DeprecationWarning,
+                stacklevel=2)
 
     if transform is not None:
         transform = guard_transform(transform)

rasterio/_base.pyx

@@ -560,11 +560,13 @@ cdef class DatasetReader(object):
         """
 
         def __get__(self):
-            warnings.warn(
+            with warnings.catch_warnings():
+                warnings.simplefilter('always')
+                warnings.warn(
                 "'src.affine' is deprecated.  Please switch to "
                 "'src.transform'. See "
                 "https://github.com/mapbox/rasterio/issues/86 for details.",
-                RuntimeWarning,
+                DeprecationWarning,
                 stacklevel=2)
             return Affine.from_gdal(*self.get_transform())
 

tests/test_deprecated.py

@@ -27,8 +27,9 @@ def test_open_transform_not_Affine(path_rgb_byte_tif):
             pass
 
 
-def test_affine_warning(path_rgb_byte_tif):
-    with pytest.warns(RuntimeWarning):
+def test_open_affine_kwarg_warning(path_rgb_byte_tif):
+    """Passing the 'affine' kwarg to rasterio.open() should raise a warning."""
+    with pytest.warns(DeprecationWarning):
         with rasterio.open(
                 path_rgb_byte_tif,
                 affine=affine.Affine.identity()) as src:
@@ -41,3 +42,10 @@ def test_guard_transform_gdal_exception(path_rgb_byte_tif):
         transform = src.transform
     with pytest.raises(ValueError):
         guard_transform(transform.to_gdal())
+
+
+def test_src_affine_warning(path_rgb_byte_tif):
+    """Calling src.affine should raise a warning."""
+    with pytest.warns(DeprecationWarning):
+        with rasterio.open(path_rgb_byte_tif) as src:
+            src.affine