diff --git a/cli/src/repl/gen.rs b/cli/src/repl/gen.rs
index 200941919d..3e789da85b 100644
--- a/cli/src/repl/gen.rs
+++ b/cli/src/repl/gen.rs
@@ -218,8 +218,8 @@ pub fn gen_and_eval<'a>(
         // Verify the module
         if let Err(errors) = env.module.verify() {
             panic!(
-                "Errors defining module: {}\n\nUncomment things nearby to see more details.",
-                errors
+                "Errors defining module:\n{}\n\nUncomment things nearby to see more details.",
+                errors.to_string()
             );
         }
 
diff --git a/compiler/gen_llvm/src/llvm/bitcode.rs b/compiler/gen_llvm/src/llvm/bitcode.rs
index 0fad482fef..2afb1c7159 100644
--- a/compiler/gen_llvm/src/llvm/bitcode.rs
+++ b/compiler/gen_llvm/src/llvm/bitcode.rs
@@ -154,18 +154,11 @@ fn build_has_tag_id_help<'a, 'ctx, 'env>(
             );
 
             let tag_data_ptr = {
-                let data_index = env
-                    .context
-                    .i64_type()
-                    .const_int(TAG_DATA_INDEX as u64, false);
+                let ptr = env
+                    .builder
+                    .build_struct_gep(tag_value, TAG_DATA_INDEX, "get_data_ptr")
+                    .unwrap();
 
-                let ptr = unsafe {
-                    env.builder.build_gep(
-                        tag_value_ptr.into_pointer_value(),
-                        &[data_index],
-                        "get_data_ptr",
-                    )
-                };
                 env.builder.build_bitcast(ptr, i8_ptr_type, "to_opaque")
             };
 
diff --git a/compiler/gen_llvm/src/llvm/build.rs b/compiler/gen_llvm/src/llvm/build.rs
index b89096f4a5..711116bc80 100644
--- a/compiler/gen_llvm/src/llvm/build.rs
+++ b/compiler/gen_llvm/src/llvm/build.rs
@@ -2532,7 +2532,10 @@ pub fn build_exp_stmt<'a, 'ctx, 'env>(
                         if align_bytes > 0 {
                             let value_ptr = value.into_pointer_value();
 
-                            if true {
+                            // We can only do this if the function itself writes data into this
+                            // pointer. If the pointer is passed as an argument, then we must copy
+                            // from one pointer to our destination pointer
+                            if value_ptr.get_first_use().is_some() {
                                 value_ptr.replace_all_uses_with(destination);
                             } else {
                                 let size = env
@@ -3382,8 +3385,7 @@ fn expose_function_to_host_help_c_abi_gen_test<'a, 'ctx, 'env>(
     // a tagged union to indicate to the test loader that a panic occurred.
     // especially when running 32-bit binaries on a 64-bit machine, there
     // does not seem to be a smarter solution
-    let wrapper_return_type =
-        roc_result_type(env, roc_function.get_type().get_return_type().unwrap());
+    let wrapper_return_type = roc_result_type(env, basic_type_from_layout(env, &return_layout));
 
     let mut cc_argument_types = Vec::with_capacity_in(arguments.len(), env.arena);
     for layout in arguments {
@@ -3861,7 +3863,7 @@ fn make_good_roc_result<'a, 'ctx, 'env>(
     let context = env.context;
     let builder = env.builder;
 
-    let v1 = roc_result_type(env, return_value.get_type()).const_zero();
+    let v1 = roc_result_type(env, basic_type_from_layout(env, &return_layout)).const_zero();
 
     let v2 = builder
         .build_insert_value(v1, context.i64_type().const_zero(), 0, "set_no_error")
@@ -3906,8 +3908,7 @@ fn make_exception_catching_wrapper<'a, 'ctx, 'env>(
         }
     };
 
-    let wrapper_return_type =
-        roc_result_type(env, roc_function.get_type().get_return_type().unwrap());
+    let wrapper_return_type = roc_result_type(env, basic_type_from_layout(env, &return_layout));
 
     // argument_types.push(wrapper_return_type.ptr_type(AddressSpace::Generic).into());
 
diff --git a/compiler/gen_llvm/src/llvm/refcounting.rs b/compiler/gen_llvm/src/llvm/refcounting.rs
index de55b101ff..0a956f8bce 100644
--- a/compiler/gen_llvm/src/llvm/refcounting.rs
+++ b/compiler/gen_llvm/src/llvm/refcounting.rs
@@ -139,8 +139,10 @@ impl<'ctx> PointerToRefcount<'ctx> {
         let block = env.builder.get_insert_block().expect("to be in a function");
         let parent = block.get_parent().unwrap();
 
-        let modify_block = env.context.append_basic_block(parent, "inc_str_modify");
-        let cont_block = env.context.append_basic_block(parent, "inc_str_cont");
+        let modify_block = env
+            .context
+            .append_basic_block(parent, "inc_refcount_modify");
+        let cont_block = env.context.append_basic_block(parent, "inc_refcount_cont");
 
         env.builder
             .build_conditional_branch(is_static_allocation, cont_block, modify_block);
@@ -1718,12 +1720,25 @@ fn modify_refcount_union_help<'a, 'ctx, 'env>(
             "cast_to_concrete_tag",
         );
 
-        // let wrapper_struct = cast_block_of_memory_to_tag(env.builder, data_bytes, wrapper_type);
-
         for (i, field_layout) in field_layouts.iter().enumerate() {
             if let Layout::RecursivePointer = field_layout {
                 panic!("non-recursive tag unions cannot contain naked recursion pointers!");
             } else if field_layout.contains_refcounted() {
+                // crazy hack
+                match field_layout {
+                    Layout::Builtin(Builtin::Str | Builtin::List(_)) => {
+                        use inkwell::attributes::{Attribute, AttributeLoc};
+                        let kind_id = Attribute::get_named_enum_kind_id("noinline");
+                        debug_assert!(kind_id > 0);
+                        let enum_attr = env.context.create_enum_attribute(kind_id, 1);
+
+                        fn_val.add_attribute(AttributeLoc::Function, enum_attr);
+                    }
+                    _ => {
+                        // do nothing
+                    }
+                }
+
                 let field_ptr = env
                     .builder
                     .build_struct_gep(cast_tag_data_pointer, i as u32, "modify_tag_field")