diff --git a/crates/sel4-capdl-initializer/add-spec/src/main.rs b/crates/sel4-capdl-initializer/add-spec/src/main.rs
index 1f8bbe093..8fb4a6989 100644
--- a/crates/sel4-capdl-initializer/add-spec/src/main.rs
+++ b/crates/sel4-capdl-initializer/add-spec/src/main.rs
@@ -4,9 +4,6 @@
 // SPDX-License-Identifier: BSD-2-Clause
 //
 
-#![feature(never_type)]
-#![feature(unwrap_infallible)]
-
 use std::fs;
 
 use anyhow::Result;
diff --git a/crates/sel4-capdl-initializer/add-spec/src/reserialize_spec.rs b/crates/sel4-capdl-initializer/add-spec/src/reserialize_spec.rs
index c987efc81..8890adc56 100644
--- a/crates/sel4-capdl-initializer/add-spec/src/reserialize_spec.rs
+++ b/crates/sel4-capdl-initializer/add-spec/src/reserialize_spec.rs
@@ -24,29 +24,26 @@ pub fn reserialize_spec<'a>(
     let mut sources = SourcesBuilder::new();
     let mut num_embedded_frames = 0;
     let final_spec: SpecWithIndirection<'a> = input_spec
-        .traverse_names_with_context::<_, !>(|named_obj| {
-            Ok(object_names_level
+        .traverse_names_with_context(|named_obj| {
+            object_names_level
                 .apply(named_obj)
                 .map(|s| IndirectObjectName {
                     range: sources.append(s.as_bytes()),
-                }))
+                })
         })
-        .into_ok()
         .split_embedded_frames(embed_frames, granule_size_bits)
-        .traverse_data::<IndirectDeflatedBytesContent, !>(|key| {
+        .traverse_data(|key| {
             let compressed = DeflatedBytesContent::pack(fill_map.get(key));
-            Ok(IndirectDeflatedBytesContent {
+            IndirectDeflatedBytesContent {
                 deflated_bytes_range: sources.append(&compressed),
-            })
+            }
         })
-        .into_ok()
-        .traverse_embedded_frames::<IndirectEmbeddedFrame, !>(|fill| {
+        .traverse_embedded_frames(|fill| {
             num_embedded_frames += 1;
             sources.align_to(granule_size);
             let range = sources.append(&fill_map.get_frame(granule_size, fill));
-            Ok(IndirectEmbeddedFrame::new(range.start))
-        })
-        .into_ok();
+            IndirectEmbeddedFrame::new(range.start)
+        });
 
     if verbose {
         eprintln!("embedded frames count: {}", num_embedded_frames);
diff --git a/crates/sel4-capdl-initializer/core/src/lib.rs b/crates/sel4-capdl-initializer/core/src/lib.rs
index 37a18f819..fcdfb6a3f 100644
--- a/crates/sel4-capdl-initializer/core/src/lib.rs
+++ b/crates/sel4-capdl-initializer/core/src/lib.rs
@@ -5,7 +5,6 @@
 //
 
 #![no_std]
-#![feature(never_type)]
 
 use core::array;
 use core::borrow::BorrowMut;
@@ -63,11 +62,11 @@ impl<'a, N: ObjectName, D: Content, M: GetEmbeddedFrame, B: BorrowMut<[PerObject
         user_image_bounds: Range<usize>,
         spec_with_sources: &SpecWithSources<N, D, M>,
         buffers: &mut InitializerBuffers<B>,
-    ) -> Result<!> {
+    ) -> ! {
         info!("Starting CapDL initializer");
 
         let (small_frame_copy_addr, large_frame_copy_addr) =
-            init_copy_addrs(bootinfo, &user_image_bounds)?;
+            init_copy_addrs(bootinfo, &user_image_bounds).unwrap();
 
         let mut cslot_allocator = CSlotAllocator::new(bootinfo.empty());
 
@@ -81,6 +80,13 @@ impl<'a, N: ObjectName, D: Content, M: GetEmbeddedFrame, B: BorrowMut<[PerObject
             buffers,
         }
         .run()
+        .unwrap_or_else(|err| panic!("Error: {}", err));
+
+        info!("CapDL initializer done, suspending");
+
+        BootInfo::init_thread_tcb().tcb_suspend().unwrap();
+
+        unreachable!()
     }
 
     fn spec(&self) -> &'a Spec<'a, N, D, M> {
@@ -93,7 +99,7 @@ impl<'a, N: ObjectName, D: Content, M: GetEmbeddedFrame, B: BorrowMut<[PerObject
 
     // // //
 
-    fn run(&mut self) -> Result<!> {
+    fn run(&mut self) -> Result<()> {
         self.create_objects()?;
 
         self.init_irqs()?;
@@ -112,11 +118,7 @@ impl<'a, N: ObjectName, D: Content, M: GetEmbeddedFrame, B: BorrowMut<[PerObject
 
         self.start_threads()?;
 
-        info!("CapDL initializer done, suspending");
-
-        BootInfo::init_thread_tcb().tcb_suspend()?;
-
-        unreachable!()
+        Ok(())
     }
 
     fn create_objects(&mut self) -> Result<()> {
diff --git a/crates/sel4-capdl-initializer/embed-spec/src/lib.rs b/crates/sel4-capdl-initializer/embed-spec/src/lib.rs
index 781e34e6a..dfa7f6e19 100644
--- a/crates/sel4-capdl-initializer/embed-spec/src/lib.rs
+++ b/crates/sel4-capdl-initializer/embed-spec/src/lib.rs
@@ -4,9 +4,6 @@
 // SPDX-License-Identifier: BSD-2-Clause
 //
 
-#![feature(never_type)]
-#![feature(unwrap_infallible)]
-
 // TODO(nspin)
 // In a few cases, we use a local const declaration to appease the borrow checker.
 // Using an exposed constructor of `Indirect` would be one way around this.
@@ -323,7 +320,7 @@ impl<'a> Embedding<'a> {
         let mut embedded_frame_count = 0usize;
         let spec = self
             .spec()
-            .traverse_data::<Ident, !>(|data| {
+            .traverse_data(|data| {
                 let id = hex::encode_upper(format!(
                     "{},{},{}",
                     data.file_range().start,
@@ -338,10 +335,9 @@ impl<'a> Embedding<'a> {
                     });
                     self.pack_fill(self.fill_map.get(data))
                 });
-                Ok(ident)
+                ident
             })
-            .into_ok()
-            .traverse_embedded_frames::<Ident, !>(|fill| {
+            .traverse_embedded_frames(|fill| {
                 let ident = format_ident!("FRAME_{}", embedded_frame_count);
                 let fname = format!("frame.{}.bin", embedded_frame_count);
                 file_inclusion_toks.extend(quote! {
@@ -351,9 +347,8 @@ impl<'a> Embedding<'a> {
                 });
                 files_for_inclusion.insert(fname, self.fill_map.get_frame(self.granule_size(), fill));
                 embedded_frame_count += 1;
-                Ok(ident)
-            })
-            .into_ok();
+                ident
+            });
 
         let types_mod = self.types_mod();
         let name_type = self.name_type(true);
diff --git a/crates/sel4-capdl-initializer/src/main.rs b/crates/sel4-capdl-initializer/src/main.rs
index c26225647..09fe85626 100644
--- a/crates/sel4-capdl-initializer/src/main.rs
+++ b/crates/sel4-capdl-initializer/src/main.rs
@@ -49,7 +49,6 @@ fn main(bootinfo: &BootInfo) -> ! {
         &spec_with_sources,
         &mut buffers,
     )
-    .unwrap_or_else(|err| panic!("Error: {}", err))
 }
 
 #[no_mangle]
diff --git a/crates/sel4-capdl-initializer/types/src/frame_init.rs b/crates/sel4-capdl-initializer/types/src/frame_init.rs
index de490390d..1166a2439 100644
--- a/crates/sel4-capdl-initializer/types/src/frame_init.rs
+++ b/crates/sel4-capdl-initializer/types/src/frame_init.rs
@@ -51,17 +51,17 @@ impl<'a, D, M> FrameInit<'a, D, M> {
     }
 }
 
-impl<'a, D> FrameInit<'a, D, !> {
+impl<'a, D> FrameInit<'a, D, NeverEmbedded> {
     #[allow(clippy::explicit_auto_deref)]
     pub const fn as_fill_infallible(&self) -> &Fill<'a, D> {
         match self {
             Self::Fill(fill) => fill,
-            Self::Embedded(never) => *never,
+            Self::Embedded(absurdity) => match *absurdity {},
         }
     }
 }
 
-impl<'a, D> object::Frame<'a, D, !> {
+impl<'a, D> object::Frame<'a, D, NeverEmbedded> {
     pub fn can_embed(&self, granule_size_bits: usize, is_root: bool) -> bool {
         is_root
             && self.paddr.is_none()
@@ -73,6 +73,11 @@ impl<'a, D> object::Frame<'a, D, !> {
 
 // // //
 
+#[derive(Copy, Clone)]
+pub enum NeverEmbedded {}
+
+// // //
+
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct EmbeddedFrame {
     ptr: *const u8,
diff --git a/crates/sel4-capdl-initializer/types/src/lib.rs b/crates/sel4-capdl-initializer/types/src/lib.rs
index 7abde3ddf..713393618 100644
--- a/crates/sel4-capdl-initializer/types/src/lib.rs
+++ b/crates/sel4-capdl-initializer/types/src/lib.rs
@@ -5,8 +5,6 @@
 //
 
 #![cfg_attr(not(feature = "std"), no_std)]
-#![feature(never_type)]
-#![feature(unwrap_infallible)]
 
 #[cfg(feature = "alloc")]
 extern crate alloc;
@@ -36,7 +34,7 @@ pub use footprint::Footprint;
 pub use frame_init::{
     BytesContent, Content, EmbeddedFrame, Fill, FillEntry, FillEntryContent,
     FillEntryContentBootInfo, FillEntryContentBootInfoId, FrameInit, GetEmbeddedFrame,
-    IndirectBytesContent, IndirectEmbeddedFrame, SelfContainedContent,
+    IndirectBytesContent, IndirectEmbeddedFrame, NeverEmbedded, SelfContainedContent,
     SelfContainedGetEmbeddedFrame,
 };
 pub use indirect::Indirect;
diff --git a/crates/sel4-capdl-initializer/types/src/traverse.rs b/crates/sel4-capdl-initializer/types/src/traverse.rs
index dd559b1c1..d61c01072 100644
--- a/crates/sel4-capdl-initializer/types/src/traverse.rs
+++ b/crates/sel4-capdl-initializer/types/src/traverse.rs
@@ -4,7 +4,11 @@
 // SPDX-License-Identifier: BSD-2-Clause
 //
 
-use crate::{object, Fill, FillEntry, FillEntryContent, FrameInit, NamedObject, Object, Spec};
+use core::convert::Infallible;
+
+use crate::{
+    object, Fill, FillEntry, FillEntryContent, FrameInit, NamedObject, NeverEmbedded, Object, Spec,
+};
 
 impl<'a, N, D, M> Spec<'a, N, D, M> {
     pub(crate) fn traverse<N1, D1, M1, E>(
@@ -51,18 +55,29 @@ impl<'a, N, D, M> Spec<'a, N, D, M> {
 }
 
 impl<'a, N, D: Clone, M: Clone> Spec<'a, N, D, M> {
-    pub fn traverse_names_with_context<N1, E>(
+    pub fn traverse_names_with_context_fallible<N1, E>(
         &self,
         f: impl FnMut(&NamedObject<'a, N, D, M>) -> Result<N1, E>,
     ) -> Result<Spec<'a, N1, D, M>, E> {
         self.traverse(f, |frame, _is_root| Ok(frame.init.clone()))
     }
 
-    pub fn traverse_names<N1, E>(
+    pub fn traverse_names_with_context<N1>(
+        &self,
+        mut f: impl FnMut(&NamedObject<'a, N, D, M>) -> N1,
+    ) -> Spec<'a, N1, D, M> {
+        unwrap_infallible(self.traverse_names_with_context_fallible(|x| Ok(f(x))))
+    }
+
+    pub fn traverse_names_fallible<N1, E>(
         &self,
         mut f: impl FnMut(&N) -> Result<N1, E>,
     ) -> Result<Spec<'a, N1, D, M>, E> {
-        self.traverse_names_with_context(|named_object| f(&named_object.name))
+        self.traverse_names_with_context_fallible(|named_object| f(&named_object.name))
+    }
+
+    pub fn traverse_names<N1>(&self, mut f: impl FnMut(&N) -> N1) -> Spec<'a, N1, D, M> {
+        unwrap_infallible(self.traverse_names_fallible(|x| Ok(f(x))))
     }
 }
 
@@ -76,7 +91,7 @@ impl<'a, N: Clone, D, M> Spec<'a, N, D, M> {
 }
 
 impl<'a, N: Clone, D, M: Clone> Spec<'a, N, D, M> {
-    pub fn traverse_data_with_context<D1, E>(
+    pub fn traverse_data_with_context_fallible<D1, E>(
         &self,
         mut f: impl FnMut(usize, &D) -> Result<D1, E>,
     ) -> Result<Spec<'a, N, D1, M>, E> {
@@ -106,16 +121,27 @@ impl<'a, N: Clone, D, M: Clone> Spec<'a, N, D, M> {
         })
     }
 
-    pub fn traverse_data<D1, E>(
+    pub fn traverse_data_with_context<D1>(
+        &self,
+        mut f: impl FnMut(usize, &D) -> D1,
+    ) -> Spec<'a, N, D1, M> {
+        unwrap_infallible(self.traverse_data_with_context_fallible(|x1, x2| Ok(f(x1, x2))))
+    }
+
+    pub fn traverse_data_fallible<D1, E>(
         &self,
         mut f: impl FnMut(&D) -> Result<D1, E>,
     ) -> Result<Spec<'a, N, D1, M>, E> {
-        self.traverse_data_with_context(|_length, data| f(data))
+        self.traverse_data_with_context_fallible(|_length, data| f(data))
+    }
+
+    pub fn traverse_data<D1>(&self, mut f: impl FnMut(&D) -> D1) -> Spec<'a, N, D1, M> {
+        unwrap_infallible(self.traverse_data_fallible(|x| Ok(f(x))))
     }
 }
 
 impl<'a, N: Clone, D: Clone, M> Spec<'a, N, D, M> {
-    pub fn traverse_embedded_frames<M1, E>(
+    pub fn traverse_embedded_frames_fallible<M1, E>(
         &self,
         mut f: impl FnMut(&M) -> Result<M1, E>,
     ) -> Result<Spec<'a, N, D, M1>, E> {
@@ -126,24 +152,33 @@ impl<'a, N: Clone, D: Clone, M> Spec<'a, N, D, M> {
             })
         })
     }
+
+    pub fn traverse_embedded_frames<M1>(&self, mut f: impl FnMut(&M) -> M1) -> Spec<'a, N, D, M1> {
+        unwrap_infallible(self.traverse_embedded_frames_fallible(|x| Ok(f(x))))
+    }
 }
 
-impl<'a, N: Clone, D: Clone> Spec<'a, N, D, !> {
+impl<'a, N: Clone, D: Clone> Spec<'a, N, D, NeverEmbedded> {
     pub fn split_embedded_frames(
         &self,
         embed_frames: bool,
         granule_size_bits: usize,
     ) -> Spec<'a, N, D, Fill<'a, D>> {
-        self.traverse_frame_init::<_, _, !>(|frame, is_root| {
-            let fill = frame.init.as_fill_infallible();
-            Ok(
-                if embed_frames && frame.can_embed(granule_size_bits, is_root) {
-                    FrameInit::Embedded(fill.clone())
-                } else {
-                    FrameInit::Fill(fill.clone())
-                },
-            )
-        })
-        .into_ok()
+        unwrap_infallible(
+            self.traverse_frame_init::<_, _, Infallible>(|frame, is_root| {
+                let fill = frame.init.as_fill_infallible();
+                Ok(
+                    if embed_frames && frame.can_embed(granule_size_bits, is_root) {
+                        FrameInit::Embedded(fill.clone())
+                    } else {
+                        FrameInit::Fill(fill.clone())
+                    },
+                )
+            }),
+        )
     }
 }
+
+fn unwrap_infallible<T>(result: Result<T, Infallible>) -> T {
+    result.unwrap_or_else(|absurdity| match absurdity {})
+}
diff --git a/crates/sel4-capdl-initializer/types/src/when_std.rs b/crates/sel4-capdl-initializer/types/src/when_std.rs
index 21a87bb4c..d064779b5 100644
--- a/crates/sel4-capdl-initializer/types/src/when_std.rs
+++ b/crates/sel4-capdl-initializer/types/src/when_std.rs
@@ -11,23 +11,21 @@ use std::ops::Deref;
 use std::os::unix::fs::FileExt;
 use std::path::{Path, PathBuf};
 
-use crate::{FileContent, FileContentRange, Fill, Spec};
+use crate::{FileContent, FileContentRange, Fill, NeverEmbedded, Spec};
 
-pub type InputSpec = Spec<'static, String, FileContentRange, !>;
+pub type InputSpec = Spec<'static, String, FileContentRange, NeverEmbedded>;
 
 impl InputSpec {
     pub fn parse(s: &str) -> Self {
         serde_json::from_str::<Spec<String, FileContent, ()>>(s)
             .unwrap()
-            .traverse_embedded_frames::<!, !>(|_| panic!())
-            .into_ok()
-            .traverse_data_with_context(|length, data| Ok::<_, !>(data.with_length(length)))
-            .into_ok()
+            .traverse_embedded_frames::<NeverEmbedded>(|_| panic!())
+            .traverse_data_with_context(|length, data| data.with_length(length))
     }
 
     pub fn collect_fill(&self, fill_dirs: impl IntoIterator<Item = impl AsRef<Path>>) -> FillMap {
         let mut builder = FillMapBuilder::new(fill_dirs);
-        self.traverse_data(|key| builder.add(key)).unwrap();
+        self.traverse_data_fallible(|key| builder.add(key)).unwrap();
         builder.build()
     }
 }
diff --git a/crates/sel4-capdl-initializer/with-embedded-spec/build-env/src/lib.rs b/crates/sel4-capdl-initializer/with-embedded-spec/build-env/src/lib.rs
index 6944c0703..01d78c2fe 100644
--- a/crates/sel4-capdl-initializer/with-embedded-spec/build-env/src/lib.rs
+++ b/crates/sel4-capdl-initializer/with-embedded-spec/build-env/src/lib.rs
@@ -4,8 +4,6 @@
 // SPDX-License-Identifier: BSD-2-Clause
 //
 
-#![feature(never_type)]
-
 use std::borrow::Cow;
 use std::env;
 use std::fs;
diff --git a/crates/sel4-capdl-initializer/with-embedded-spec/embedded-spec/validate/src/lib.rs b/crates/sel4-capdl-initializer/with-embedded-spec/embedded-spec/validate/src/lib.rs
index a9e7a3f2a..1c8ffeb0c 100644
--- a/crates/sel4-capdl-initializer/with-embedded-spec/embedded-spec/validate/src/lib.rs
+++ b/crates/sel4-capdl-initializer/with-embedded-spec/embedded-spec/validate/src/lib.rs
@@ -4,9 +4,6 @@
 // SPDX-License-Identifier: BSD-2-Clause
 //
 
-#![feature(never_type)]
-#![feature(unwrap_infallible)]
-
 use std::slice;
 
 use sel4_capdl_initializer_types::*;
@@ -23,38 +20,30 @@ pub fn run(tell_cargo: bool) {
 
     let embedded = &sel4_capdl_initializer_with_embedded_spec_embedded_spec::SPEC;
     let adapted_embedded: SpecCommon = embedded
-        .traverse_names_with_context::<_, !>(|named_obj| {
-            Ok(named_obj.name.inner().to_common().map(ToOwned::to_owned))
+        .traverse_names_with_context(|named_obj| {
+            named_obj.name.inner().to_common().map(ToOwned::to_owned)
         })
-        .into_ok()
-        .traverse_data_with_context::<_, !>(|length, data| {
+        .traverse_data_with_context(|length, data| {
             let mut buf = vec![0; length];
             data.inner().self_contained_copy_out(&mut buf);
-            Ok(buf)
-        })
-        .into_ok()
-        .traverse_embedded_frames::<_, !>(|frame| {
-            Ok(unsafe {
-                slice::from_raw_parts(frame.inner().ptr(), embedding.granule_size()).to_vec()
-            })
+            buf
         })
-        .into_ok();
+        .traverse_embedded_frames(|frame| unsafe {
+            slice::from_raw_parts(frame.inner().ptr(), embedding.granule_size()).to_vec()
+        });
 
     let input = &embedding.spec;
     let adapted_input: SpecCommon = input
-        .traverse_names_with_context::<_, !>(|named_obj| {
-            Ok(embedding
+        .traverse_names_with_context(|named_obj| {
+            embedding
                 .object_names_level
                 .apply(named_obj)
-                .map(Clone::clone))
-        })
-        .into_ok()
-        .traverse_data::<_, !>(|key| Ok(embedding.fill_map.get(key).to_vec()))
-        .into_ok()
-        .traverse_embedded_frames::<_, !>(|fill| {
-            Ok(embedding.fill_map.get_frame(embedding.granule_size(), fill))
+                .map(Clone::clone)
         })
-        .into_ok();
+        .traverse_data(|key| embedding.fill_map.get(key).to_vec())
+        .traverse_embedded_frames(|fill| {
+            embedding.fill_map.get_frame(embedding.granule_size(), fill)
+        });
 
     if adapted_embedded != adapted_input {
         // NOTE for debugging:
diff --git a/crates/sel4-capdl-initializer/with-embedded-spec/src/main.rs b/crates/sel4-capdl-initializer/with-embedded-spec/src/main.rs
index df8c7d103..b295231fd 100644
--- a/crates/sel4-capdl-initializer/with-embedded-spec/src/main.rs
+++ b/crates/sel4-capdl-initializer/with-embedded-spec/src/main.rs
@@ -42,7 +42,6 @@ fn main(bootinfo: &BootInfo) -> ! {
     Initializer::initialize(bootinfo, user_image_bounds(), &spec_with_sources, unsafe {
         &mut BUFFERS
     })
-    .unwrap_or_else(|err| panic!("Error: {}", err))
 }
 
 extern "C" {