diff --git a/tests/pipeline/test_blaze.py b/tests/pipeline/test_blaze.py
index cf5cb1c8..29885a30 100644
--- a/tests/pipeline/test_blaze.py
+++ b/tests/pipeline/test_blaze.py
@@ -21,7 +21,7 @@ from toolz.curried import operator as op
 
 from zipline.assets.synthetic import make_simple_equity_info
 from zipline.pipeline import Pipeline, CustomFactor
-from zipline.pipeline.data import DataSet, BoundColumn
+from zipline.pipeline.data import DataSet, BoundColumn, Column
 from zipline.pipeline.engine import SimplePipelineEngine
 from zipline.pipeline.loaders.blaze import (
     from_blaze,
@@ -29,16 +29,21 @@ from zipline.pipeline.loaders.blaze import (
     NoMetaDataWarning,
 )
 from zipline.pipeline.loaders.blaze.core import (
+    ExprData,
     NonPipelineField,
 )
-from zipline.testing import parameter_space
+from zipline.testing import (
+    ZiplineTestCase,
+    parameter_space,
+    tmp_asset_finder,
+)
 from zipline.testing.fixtures import WithAssetFinder
 from zipline.utils.numpy_utils import (
     float64_dtype,
     int64_dtype,
     repeat_last_axis,
 )
-from zipline.testing import tmp_asset_finder, ZiplineTestCase
+from zipline.testing.predicates import assert_equal, assert_isidentical
 
 nameof = op.attrgetter('name')
 dtypeof = op.attrgetter('dtype')
@@ -208,6 +213,108 @@ class BlazeToPipelineTestCase(WithAssetFinder, ZiplineTestCase):
         self.assertIn("'asof_date'", str(e.exception))
         self.assertIn(repr(str(expr.dshape.measure)), str(e.exception))
 
+    def test_missing_timestamp(self):
+        expr = bz.data(
+            self.df.loc[:, ['sid', 'value', 'asof_date']],
+            name='expr',
+            dshape="""
+            var * {
+                sid: ?int64,
+                value: float64,
+                asof_date: datetime,
+            }""",
+        )
+
+        loader = BlazeLoader()
+
+        from_blaze(
+            expr,
+            loader=loader,
+            no_deltas_rule='ignore',
+            no_checkpoints_rule='ignore',
+        )
+
+        self.assertEqual(len(loader), 1)
+        exprdata, = loader.values()
+
+        assert_isidentical(
+            exprdata.expr,
+            bz.transform(expr, timestamp=expr.asof_date),
+        )
+
+    def test_from_blaze_no_resources_dataset_expr(self):
+        expr = bz.symbol('expr', self.dshape)
+
+        with self.assertRaises(ValueError) as e:
+            from_blaze(
+                expr,
+                loader=self.garbage_loader,
+                no_deltas_rule='ignore',
+                no_checkpoints_rule='ignore',
+                missing_values=self.missing_values,
+            )
+        assert_equal(
+            str(e.exception),
+            'no resources provided to compute expr',
+        )
+
+    @parameter_space(metadata={'deltas', 'checkpoints'})
+    def test_from_blaze_no_resources_metadata_expr(self, metadata):
+        expr = bz.data(self.df, name='expr', dshape=self.dshape)
+        metadata_expr = bz.symbol('metadata', self.dshape)
+
+        with self.assertRaises(ValueError) as e:
+            from_blaze(
+                expr,
+                loader=self.garbage_loader,
+                no_deltas_rule='ignore',
+                no_checkpoints_rule='ignore',
+                missing_values=self.missing_values,
+                **{metadata: metadata_expr}
+            )
+        assert_equal(
+            str(e.exception),
+            'no resources provided to compute %s' % metadata,
+        )
+
+    def test_from_blaze_mixed_resources_dataset_expr(self):
+        expr = bz.data(self.df, name='expr', dshape=self.dshape)
+
+        with self.assertRaises(ValueError) as e:
+            from_blaze(
+                expr,
+                resources={expr: self.df},
+                loader=self.garbage_loader,
+                no_deltas_rule='ignore',
+                no_checkpoints_rule='ignore',
+                missing_values=self.missing_values,
+            )
+        assert_equal(
+            str(e.exception),
+            'explicit and implicit resources provided to compute expr',
+        )
+
+    @parameter_space(metadata={'deltas', 'checkpoints'})
+    def test_from_blaze_mixed_resources_metadata_expr(self, metadata):
+        expr = bz.symbol('expr', self.dshape)
+        metadata_expr = bz.data(self.df, name=metadata, dshape=self.dshape)
+
+        with self.assertRaises(ValueError) as e:
+            from_blaze(
+                expr,
+                resources={metadata_expr: self.df},
+                loader=self.garbage_loader,
+                no_deltas_rule='ignore',
+                no_checkpoints_rule='ignore',
+                missing_values=self.missing_values,
+                **{metadata: metadata_expr}
+            )
+        assert_equal(
+            str(e.exception),
+            'explicit and implicit resources provided to compute %s' %
+            metadata,
+        )
+
     @parameter_space(deltas={True, False}, checkpoints={True, False})
     def test_auto_metadata(self, deltas, checkpoints):
         select_level = op.getitem(('ignore', 'raise'))
@@ -1486,3 +1593,43 @@ class BlazeToPipelineTestCase(WithAssetFinder, ZiplineTestCase):
                 window_length=1,
                 compute_fn=op.itemgetter(-1),
             )
+
+
+class MiscTestCase(ZiplineTestCase):
+    def test_exprdata_repr(self):
+        strd = set()
+
+        class BadRepr(object):
+            """A class which cannot be repr'd.
+            """
+            def __init__(self, name):
+                self._name = name
+
+            def __repr__(self):  # pragma: no cover
+                raise AssertionError('ayy')
+
+            def __str__(self):
+                strd.add(self)
+                return self._name
+
+        assert_equal(
+            repr(ExprData(
+                expr=BadRepr('expr'),
+                deltas=BadRepr('deltas'),
+                checkpoints=BadRepr('checkpoints'),
+                odo_kwargs={'a': 'b'},
+            )),
+            "ExprData(expr='expr', deltas='deltas',"
+            " checkpoints='checkpoints', odo_kwargs={'a': 'b'})",
+        )
+
+    def test_blaze_loader_repr(self):
+        assert_equal(repr(BlazeLoader()), '<BlazeLoader: {}>')
+
+    def test_blaze_loader_lookup_failure(self):
+        class D(DataSet):
+            c = Column(dtype='float64')
+
+        with self.assertRaises(KeyError) as e:
+            BlazeLoader()(D.c)
+        assert_equal(str(e.exception), 'D.c::float64')
diff --git a/zipline/pipeline/loaders/blaze/core.py b/zipline/pipeline/loaders/blaze/core.py
index a23d5b70..47cf5967 100644
--- a/zipline/pipeline/loaders/blaze/core.py
+++ b/zipline/pipeline/loaders/blaze/core.py
@@ -140,7 +140,6 @@ from __future__ import division, absolute_import
 from abc import ABCMeta, abstractproperty
 from collections import namedtuple, defaultdict
 from copy import copy
-import datetime
 from functools import partial
 from itertools import count
 import warnings
@@ -240,7 +239,7 @@ class ExprData(namedtuple('ExprData', 'expr deltas checkpoints odo_kwargs')):
         return super(ExprData, cls).__repr__(cls(
             str(self.expr),
             str(self.deltas),
-            str(self.checkpoint),
+            str(self.checkpoints),
             self.odo_kwargs,
         ))
 
@@ -257,7 +256,7 @@ class InvalidField(with_metaclass(ABCMeta)):
         The shape of the field.
     """
     @abstractproperty
-    def error_format(self):
+    def error_format(self):  # pragma: no cover
         raise NotImplementedError('error_format')
 
     def __init__(self, field, type_):
@@ -282,14 +281,6 @@ class NonPipelineField(InvalidField):
     )
 
 
-class NotPipelineCompatible(TypeError):
-    """Exception used to indicate that a dshape is not Pipeline API
-    compatible.
-    """
-    def __str__(self):
-        return "'%s' is a non Pipeline API compatible type'" % self.args
-
-
 _new_names = ('BlazeDataSet_%d' % n for n in count())
 
 
@@ -369,7 +360,7 @@ def new_dataset(expr, deltas, missing_values):
 
     # unicode is a name error in py3 but the branch is only hit
     # when we are in python 2.
-    if PY2 and isinstance(name, unicode):  # noqa
+    if PY2 and isinstance(name, unicode):  # pragma: no cover # noqa
         name = name.encode('utf-8')
 
     return type(name, (DataSet,), columns)
@@ -674,8 +665,9 @@ def from_blaze(expr,
         )
 
     # Ensure that we have a data resource to execute the query against.
-    _check_resources('dataset_expr', dataset_expr, resources)
+    _check_resources('expr', dataset_expr, resources)
     _check_resources('deltas', deltas, resources)
+    _check_resources('checkpoints', checkpoints, resources)
 
     # Create or retrieve the Pipeline API dataset.
     if missing_values is None:
@@ -883,31 +875,6 @@ def adjustments_from_deltas_with_sids(dense_dates,
     return dict(adjustments)  # no subclasses of dict
 
 
-def _checkpoint_ts(lower_dt):
-    """Given a lower time bound for a query, get the date in the checkpoint
-    table to query for.
-
-    Parameters
-    ----------
-    lower_dt : datetime
-        The lower time bound for the query.
-
-    Returns
-    -------
-    checkpoint_ts : pd.Timestamp
-        The date in the checkpoint table to query for.
-    """
-    date = lower_dt.date()
-    return pd.Timestamp.combine(
-        date.replace(
-            day=1,
-            month=(date.month - 2) % 12 + 1,
-            year=date.year - 1 if date.month == 1 else date.year,
-        ),
-        datetime.time(0),
-    ).tz_localize('US/Eastern')
-
-
 class BlazeLoader(dict):
     """A PipelineLoader for datasets constructed with ``from_blaze``.
 
@@ -945,6 +912,12 @@ class BlazeLoader(dict):
             return self
         raise KeyError(column)
 
+    def __repr__(self):
+        return '<%s: %s>' % (
+            type(self).__name__,
+            super(BlazeLoader, self).__repr__(),
+        )
+
     def load_adjusted_array(self, columns, dates, assets, mask):
         return dict(
             concat(map(
diff --git a/zipline/testing/predicates.py b/zipline/testing/predicates.py
index 3bc35346..ed1c472c 100644
--- a/zipline/testing/predicates.py
+++ b/zipline/testing/predicates.py
@@ -380,6 +380,12 @@ def assert_timestamp_and_datetime_equal(result,
     )
 
 
+def assert_isidentical(result, expected, msg=''):
+    assert result.isidentical(expected), (
+        '%s%s is not identical to %s' % (_fmt_msg(msg), result, expected)
+    )
+
+
 try:
     # pull the dshape cases in
     from datashape.util.testing import assert_dshape_equal