Fix release build cfg issues

src/key_value_stores/bigtable.rs

@@ -21,8 +21,6 @@ use metrics::{counter, describe_histogram, histogram, Unit};
 use tracing::{instrument, trace};
 use url::Url;
 
-#[cfg(debug_assertions)]
-use crate::memory_used::MemoryUsed;
 use crate::{pipeline::CONCURRENCY, Result};
 
 use super::{KeyValueStore, KeyValueStoreNew, PipelinedGet, PipelinedSet};
@@ -216,11 +214,18 @@ impl<'store> PipelinedGet<'store> for BigTablePipelinedGet<'store> {
                 return Err(err).context("error checking BigTable for cached values");
             }
         };
-        debug_assert!(
-            response.memory_used() < 1024 * 1024,
-            "BigTable response is using far too much memory: {} bytes",
-            response.memory_used()
-        );
+
+        // Check for giant cache entries.
+        #[cfg(debug_assertions)]
+        {
+            use crate::memory_used::MemoryUsed;
+            let memory_used = response.memory_used();
+            debug_assert!(
+                memory_used < 1024 * 1024,
+                "BigTable response is using far too much memory: {} bytes",
+                memory_used
+            );
+        }
 
         histogram!(
             "geocodecsv.bigtable.get_request.duration_seconds",