diff --git a/pyop2/caching.py b/pyop2/caching.py
index 4771de511..6e0d47a36 100644
--- a/pyop2/caching.py
+++ b/pyop2/caching.py
@@ -402,12 +402,12 @@ class DEFAULT_CACHE(dict):
     pass
 
 
-# Examples of how to instrument and use different default caches:
-# ~ DEFAULT_CACHE = instrument(DEFAULT_CACHE)
-# ~ DEFAULT_CACHE = instrument(cachetools.LRUCache)
-# ~ DEFAULT_CACHE = partial(DEFAULT_CACHE, maxsize=100)
+# Example of how to instrument and use different default caches:
 EXOTIC_CACHE = partial(instrument(cachetools.LRUCache), maxsize=100)
-# ~ DictLikeDiskAccess = instrument(DictLikeDiskAccess)
+# Turn on cache measurements if printing cache info is enabled
+if configuration["print_cache_info"] or _running_on_ci:
+    DEFAULT_CACHE = instrument(DEFAULT_CACHE)
+    DictLikeDiskAccess = instrument(DictLikeDiskAccess)
 
 
 # JBTODO: This functionality should only be enabled with a PYOP2_SPMD_STRICT
@@ -509,7 +509,6 @@ def wrapper(*args, **kwargs):
     return decorator
 
 
-# JBTODO: This needs some more thought
 def clear_memory_cache(comm):
     with temp_internal_comm(comm) as icomm:
         if icomm.Get_attr(comm_cache_keyval) is not None:
@@ -540,6 +539,6 @@ def decorator(func):
 # * Refactor compilation.py to use @mem_and_disk_cached, where get_so is just uses DictLikeDiskAccess with an overloaded self.write() method ✓
 # * Systematic investigation into cache sizes/types for Firedrake
 #   - Is a mem cache needed for DLLs? ~~No~~ Yes!!
-#   - Is LRUCache better than a simple dict? (memory profile test suite)
-#   - What is the optimal maxsize?
+#   - Is LRUCache better than a simple dict? (memory profile test suite) No
+#   - What is the optimal maxsize? ∞
 # * Add some docstrings and maybe some exposition!
diff --git a/pyop2/compilation.py b/pyop2/compilation.py
index ce45c7e99..c7a278feb 100644
--- a/pyop2/compilation.py
+++ b/pyop2/compilation.py
@@ -68,8 +68,10 @@ def _check_hashes(x, y, datatype):
 
 _check_op = mpi.MPI.Op.Create(_check_hashes, commute=True)
 _compiler = None
-# Directory must be unique per user for shared machines
-MEM_TMP_DIR = Path(gettempdir()).joinpath(f"pyop2-tempcache-uid{os.getuid()}")
+# Directory must be unique per VENV for multiple installs
+# _and_ per user for shared machines
+_EXE_HASH = md5(sys.executable.encode()).hexdigest()[-6:]
+MEM_TMP_DIR = Path(gettempdir()).joinpath(f"pyop2-tempcache-uid{os.getuid()}").joinpath(_EXE_HASH)
 
 
 def set_default_compiler(compiler):
@@ -678,9 +680,8 @@ def _add_profiling_events(dll, events):
             ctypes.c_int.in_dll(dll, 'ID_'+e).value = PETSc.Log.Event(e).id
 
 
-# JBTODO: Move to caching??
-def clear_cache(prompt=False):
-    """Clear the PyOP2 compiler cache.
+def clear_compiler_disk_cache(prompt=False):
+    """Clear the PyOP2 compiler disk cache.
 
     :arg prompt: if ``True`` prompt before removing any files
     """
diff --git a/scripts/pyop2-clean b/scripts/pyop2-clean
index ab29f1245..52f667ec4 100755
--- a/scripts/pyop2-clean
+++ b/scripts/pyop2-clean
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
-from pyop2.compilation import clear_cache
+from pyop2.compilation import clear_compiler_disk_cache
 
 
 if __name__ == '__main__':
-    clear_cache(prompt=True)
+    clear_compiler_disk_cache(prompt=True)