Git dependencies, skip dropping ServeSession

src/cli/build.rs

@@ -1,5 +1,6 @@
 use std::{
     io::{BufWriter, Write},
+    mem::ManuallyDrop,
     path::{Path, PathBuf},
 };
 
@@ -61,6 +62,14 @@ impl BuildCommand {
             }
         }
 
+        // Never drop ServeSession, because it's VERY expensive to drop and
+        // we're about to exit anyways.
+        //
+        // This is kind of evil; if this function is ever called outside of the
+        // context of a CLI, this will leak a large object forever. However, the
+        // performance benefits of leaking it outweigh the cost at this time.
+        let _session = ManuallyDrop::new(session);
+
         Ok(())
     }
 }