diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 85e0336b046b1fbad50c7e969efb46daae3e9f3b..0b1f8156ce5bd76b28b947c1441f22bac567ed7e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -107,10 +107,15 @@ jobs:
         -   uses: actions/checkout@v4
         -   name: "Main Script"
             run: |
+                # This test makes sure that loopy can run with kernels loaded from disk cache.
                 curl -L -O https://tiker.net/ci-support-v0
                 . ./ci-support-v0
                 build_py_project_in_conda_env
                 ( test_py_project )
+
+                # See https://github.com/inducer/loopy/pull/828 why this is disabled.
+                # export LOOPY_ABORT_ON_CACHE_MISS=1
+
                 ( test_py_project )
 
     examples:
diff --git a/doc/ref_other.rst b/doc/ref_other.rst
index 538f0cdb924507cb502a8eecf30a48ece3909f56..81b6eca1e8e637cd80cab72e738e02adbe53a7d2 100644
--- a/doc/ref_other.rst
+++ b/doc/ref_other.rst
@@ -25,6 +25,13 @@ Controlling caching
     is suppressed.
 
 
+.. envvar:: LOOPY_ABORT_ON_CACHE_MISS
+
+    If set to a string that :func:`pytools.strtobool` evaluates as ``True``,
+    loopy will raise an exception if a cache miss occurs. This can be useful
+    for debugging cache-related issues. For example, it can be used to automatically test whether caching is successful for a particular code, by setting this variable to ``True`` and re-running the code.
+
+
 .. autofunction:: set_caching_enabled
 
 .. autoclass:: CacheMode
diff --git a/loopy/__init__.py b/loopy/__init__.py
index 7a1942f3d9446e71560f457239f182791f66472d..8060ee0bc796b7cb6c0cd37a516e249b44b831bb 100644
--- a/loopy/__init__.py
+++ b/loopy/__init__.py
@@ -509,6 +509,9 @@ CACHING_ENABLED = (
     not strtobool(os.environ.get("CG_NO_CACHE", "false")))
 
 
+ABORT_ON_CACHE_MISS = strtobool(os.environ.get("LOOPY_ABORT_ON_CACHE_MISS", "false"))
+
+
 def set_caching_enabled(flag):
     """Set whether :mod:`loopy` is allowed to use disk caching for its various
     code generation stages.
diff --git a/loopy/codegen/__init__.py b/loopy/codegen/__init__.py
index 3de36e242e34b93340c914f742db0d46cb5d3539..e7decb8f25091ab39e16422b7e4ce423b50baff3 100644
--- a/loopy/codegen/__init__.py
+++ b/loopy/codegen/__init__.py
@@ -549,7 +549,8 @@ class TranslationUnitCodeGenerationResult:
 
 def generate_code_v2(t_unit: TranslationUnit) -> CodeGenerationResult:
     # {{{ cache retrieval
-    from loopy import CACHING_ENABLED
+
+    from loopy import ABORT_ON_CACHE_MISS, CACHING_ENABLED
     from loopy.kernel import LoopKernel
     from loopy.translation_unit import make_program
 
@@ -563,6 +564,8 @@ def generate_code_v2(t_unit: TranslationUnit) -> CodeGenerationResult:
         except KeyError:
             logger.debug(f"TranslationUnit with entrypoints {t_unit.entrypoints}:"
                           " code generation cache miss")
+            if ABORT_ON_CACHE_MISS:
+                raise
 
     # }}}
 
diff --git a/test/test_c_execution.py b/test/test_c_execution.py
index 9943d41df8330f765509db6339f57ef3a263a4d4..33e50e3ab1eea4645d6df3bfc8899b6ece5e1b5d 100644
--- a/test/test_c_execution.py
+++ b/test/test_c_execution.py
@@ -93,10 +93,11 @@ def test_c_target_strides():
 
 def test_c_target_strides_nonsquare():
     from loopy.target.c import ExecutableCTarget
+    rng = np.random.default_rng(seed=42)
 
     def __get_kernel(order="C"):
         indices = ["i", "j", "k"]
-        sizes = tuple(np.random.randint(1, 11, size=len(indices)))
+        sizes = tuple(rng.integers(1, 11, size=len(indices)))
         # create domain strings
         domain_template = "{{ [{iname}]: 0 <= {iname} < {size} }}"
         domains = []
@@ -141,9 +142,11 @@ def test_c_target_strides_nonsquare():
 def test_c_optimizations():
     from loopy.target.c import ExecutableCTarget
 
+    rng = np.random.default_rng(seed=42)
+
     def __get_kernel(order="C"):
         indices = ["i", "j", "k"]
-        sizes = tuple(np.random.randint(1, 11, size=len(indices)))
+        sizes = tuple(rng.integers(1, 11, size=len(indices)))
         # create domain strings
         domain_template = "{{ [{iname}]: 0 <= {iname} < {size} }}"
         domains = []