diff --git a/crates/compiler/builtins/roc/List.roc b/crates/compiler/builtins/roc/List.roc
index f74e39ceabc..efba31324d3 100644
--- a/crates/compiler/builtins/roc/List.roc
+++ b/crates/compiler/builtins/roc/List.roc
@@ -874,7 +874,7 @@ map_with_index_help = \src, dest, func, index, length ->
 ## All of these options are compatible with the others. For example, you can use `At` or `After`
 ## with `start` regardless of what `end` and `step` are set to.
 range : _
-range = \{ start, end, step ? 0 } ->
+range = \{ start, end, step ?? 0 } ->
     { calc_next, step_is_positive } =
         if step == 0 then
             when T(start, end) is
diff --git a/crates/compiler/builtins/roc/Num.roc b/crates/compiler/builtins/roc/Num.roc
index 906dc43207e..9c237839363 100644
--- a/crates/compiler/builtins/roc/Num.roc
+++ b/crates/compiler/builtins/roc/Num.roc
@@ -617,8 +617,8 @@ is_gte : Num a, Num a -> Bool
 ##
 ## If either argument is [*NaN*](Num.is_nan), returns `Bool.false` no matter what. (*NaN*
 ## is [defined to be unordered](https://en.wikipedia.org/wiki/NaN#Comparison_with_NaN).)
-is_approx_eq : Frac a, Frac a, { rtol ? Frac a, atol ? Frac a } -> Bool
-is_approx_eq = \x, y, { rtol ? 0.00001, atol ? 0.00000001 } ->
+is_approx_eq : Frac a, Frac a, { rtol ?? Frac a, atol ?? Frac a } -> Bool
+is_approx_eq = \x, y, { rtol ?? 0.00001, atol ?? 0.00000001 } ->
     eq = x <= y && x >= y
     meets_tolerance = Num.abs_diff(x, y) <= Num.max(atol, (rtol * Num.max(Num.abs(x), Num.abs(y))))
     eq || meets_tolerance
diff --git a/crates/compiler/fmt/src/annotation.rs b/crates/compiler/fmt/src/annotation.rs
index eff2c010307..45d3ee2ee82 100644
--- a/crates/compiler/fmt/src/annotation.rs
+++ b/crates/compiler/fmt/src/annotation.rs
@@ -386,7 +386,7 @@ impl<'a> Nodify<'a> for AssignedField<'a, TypeAnnotation<'a>> {
                 assigned_field_value_to_node(n.into_bump_str(), arena, sp, &value.value, ":", flags)
             }
             AssignedField::OptionalValue(name, sp, value) => {
-                assigned_field_value_to_node(name.value, arena, sp, &value.value, "?", flags)
+                assigned_field_value_to_node(name.value, arena, sp, &value.value, "??", flags)
             }
             AssignedField::LabelOnly(name) => NodeInfo {
                 before: &[],
@@ -512,7 +512,7 @@ fn format_assigned_field_help<T>(
 
             buf.spaces(separator_spaces);
             buf.indent(indent);
-            buf.push('?');
+            buf.push_str("??");
             buf.spaces(1);
             ann.value.format(buf, indent);
         }
diff --git a/crates/compiler/fmt/src/expr.rs b/crates/compiler/fmt/src/expr.rs
index 1dd9427f08a..149ec457064 100644
--- a/crates/compiler/fmt/src/expr.rs
+++ b/crates/compiler/fmt/src/expr.rs
@@ -701,16 +701,8 @@ fn fmt_apply(
     if !expr.before.is_empty() {
         format_spaces(buf, expr.before, Newlines::Yes, indent);
     }
-    expr.item.format_with_options(
-        buf,
-        if use_commas_and_parens {
-            Parens::NotNeeded
-        } else {
-            Parens::InApply
-        },
-        Newlines::Yes,
-        indent,
-    );
+    expr.item
+        .format_with_options(buf, Parens::InApply, Newlines::Yes, indent);
 
     if use_commas_and_parens {
         buf.push('(');
diff --git a/crates/compiler/fmt/src/pattern.rs b/crates/compiler/fmt/src/pattern.rs
index b256e47f918..ef65e277417 100644
--- a/crates/compiler/fmt/src/pattern.rs
+++ b/crates/compiler/fmt/src/pattern.rs
@@ -268,7 +268,7 @@ fn fmt_pattern_only(
         Pattern::OptionalField(name, loc_pattern) => {
             buf.indent(indent);
             snakify_camel_ident(buf, name);
-            buf.push_str(" ?");
+            buf.push_str(" ??");
             buf.spaces(1);
             loc_pattern.format(buf, indent);
         }
diff --git a/crates/compiler/load/tests/test_reporting.rs b/crates/compiler/load/tests/test_reporting.rs
index 8adf461aa0d..f4dd519ade9 100644
--- a/crates/compiler/load/tests/test_reporting.rs
+++ b/crates/compiler/load/tests/test_reporting.rs
@@ -4541,8 +4541,8 @@ mod test_reporting {
     4│      f : { foo  bar }
                        ^
 
-    I was expecting to see a colon, question mark, comma or closing curly
-    brace.
+    I was expecting to see a colon, two question marks (??), comma or
+    closing curly brace.
     "
     );
 
diff --git a/crates/compiler/parse/src/expr.rs b/crates/compiler/parse/src/expr.rs
index 715520f39b8..cc076385a82 100644
--- a/crates/compiler/parse/src/expr.rs
+++ b/crates/compiler/parse/src/expr.rs
@@ -3587,7 +3587,10 @@ pub fn record_field<'a>() -> impl Parser<'a, RecordField<'a>, ERecord<'a>> {
                     optional(either(
                         and(byte(b':', ERecord::Colon), record_field_expr()),
                         and(
-                            byte(b'?', ERecord::QuestionMark),
+                            and(
+                                byte(b'?', ERecord::QuestionMark),
+                                optional(byte(b'?', ERecord::SecondQuestionMark)),
+                            ),
                             spaces_before(specialize_err_ref(ERecord::Expr, loc_expr(true))),
                         ),
                     )),
diff --git a/crates/compiler/parse/src/normalize.rs b/crates/compiler/parse/src/normalize.rs
index 6ab1abad0ec..857adb01aeb 100644
--- a/crates/compiler/parse/src/normalize.rs
+++ b/crates/compiler/parse/src/normalize.rs
@@ -1219,6 +1219,7 @@ impl<'a> Normalize<'a> for ERecord<'a> {
             ERecord::UnderscoreField(_pos) => ERecord::Field(Position::zero()),
             ERecord::Colon(_) => ERecord::Colon(Position::zero()),
             ERecord::QuestionMark(_) => ERecord::QuestionMark(Position::zero()),
+            ERecord::SecondQuestionMark(_) => ERecord::SecondQuestionMark(Position::zero()),
             ERecord::Arrow(_) => ERecord::Arrow(Position::zero()),
             ERecord::Ampersand(_) => ERecord::Ampersand(Position::zero()),
             ERecord::Expr(inner_err, _) => {
@@ -1393,6 +1394,9 @@ impl<'a> Normalize<'a> for ETypeAbilityImpl<'a> {
                 ETypeAbilityImpl::Space(*inner_err, Position::zero())
             }
             ETypeAbilityImpl::QuestionMark(_) => ETypeAbilityImpl::QuestionMark(Position::zero()),
+            ETypeAbilityImpl::SecondQuestionMark(_) => {
+                ETypeAbilityImpl::SecondQuestionMark(Position::zero())
+            }
             ETypeAbilityImpl::Ampersand(_) => ETypeAbilityImpl::Ampersand(Position::zero()),
             ETypeAbilityImpl::Expr(inner_err, _) => {
                 ETypeAbilityImpl::Expr(arena.alloc(inner_err.normalize(arena)), Position::zero())
@@ -1471,7 +1475,8 @@ impl<'a> Normalize<'a> for ETypeRecord<'a> {
             ETypeRecord::Open(_) => ETypeRecord::Open(Position::zero()),
             ETypeRecord::Field(_) => ETypeRecord::Field(Position::zero()),
             ETypeRecord::Colon(_) => ETypeRecord::Colon(Position::zero()),
-            ETypeRecord::Optional(_) => ETypeRecord::Optional(Position::zero()),
+            ETypeRecord::OptionalFirst(_) => ETypeRecord::OptionalFirst(Position::zero()),
+            ETypeRecord::OptionalSecond(_) => ETypeRecord::OptionalSecond(Position::zero()),
             ETypeRecord::Type(inner_err, _) => {
                 ETypeRecord::Type(arena.alloc(inner_err.normalize(arena)), Position::zero())
             }
@@ -1491,7 +1496,8 @@ impl<'a> Normalize<'a> for PRecord<'a> {
             PRecord::Open(_) => PRecord::Open(Position::zero()),
             PRecord::Field(_) => PRecord::Field(Position::zero()),
             PRecord::Colon(_) => PRecord::Colon(Position::zero()),
-            PRecord::Optional(_) => PRecord::Optional(Position::zero()),
+            PRecord::OptionalFirst(_) => PRecord::OptionalFirst(Position::zero()),
+            PRecord::OptionalSecond(_) => PRecord::OptionalSecond(Position::zero()),
             PRecord::Pattern(inner_err, _) => {
                 PRecord::Pattern(arena.alloc(inner_err.normalize(arena)), Position::zero())
             }
diff --git a/crates/compiler/parse/src/parser.rs b/crates/compiler/parse/src/parser.rs
index acc9b53b1a5..500be5bc846 100644
--- a/crates/compiler/parse/src/parser.rs
+++ b/crates/compiler/parse/src/parser.rs
@@ -683,6 +683,7 @@ pub enum ERecord<'a> {
     UnderscoreField(Position),
     Colon(Position),
     QuestionMark(Position),
+    SecondQuestionMark(Position),
     Arrow(Position),
     Ampersand(Position),
 
@@ -706,6 +707,7 @@ impl<'a> ERecord<'a> {
             | ERecord::UnderscoreField(p)
             | ERecord::Colon(p)
             | ERecord::QuestionMark(p)
+            | ERecord::SecondQuestionMark(p)
             | ERecord::Arrow(p)
             | ERecord::Ampersand(p)
             | ERecord::Space(_, p) => Region::from_pos(*p),
@@ -1107,7 +1109,8 @@ pub enum PRecord<'a> {
 
     Field(Position),
     Colon(Position),
-    Optional(Position),
+    OptionalFirst(Position),
+    OptionalSecond(Position),
 
     Pattern(&'a EPattern<'a>, Position),
     Expr(&'a EExpr<'a>, Position),
@@ -1127,7 +1130,8 @@ impl<'a> PRecord<'a> {
             | PRecord::Open(p)
             | PRecord::Field(p)
             | PRecord::Colon(p)
-            | PRecord::Optional(p)
+            | PRecord::OptionalFirst(p)
+            | PRecord::OptionalSecond(p)
             | PRecord::Space(_, p) => Region::from_pos(*p),
         }
     }
@@ -1244,7 +1248,8 @@ pub enum ETypeRecord<'a> {
 
     Field(Position),
     Colon(Position),
-    Optional(Position),
+    OptionalFirst(Position),
+    OptionalSecond(Position),
     Type(&'a EType<'a>, Position),
 
     Space(BadInputError, Position),
@@ -1266,7 +1271,8 @@ impl<'a> ETypeRecord<'a> {
             | ETypeRecord::Open(p)
             | ETypeRecord::Field(p)
             | ETypeRecord::Colon(p)
-            | ETypeRecord::Optional(p)
+            | ETypeRecord::OptionalFirst(p)
+            | ETypeRecord::OptionalSecond(p)
             | ETypeRecord::Space(_, p)
             | ETypeRecord::IndentOpen(p)
             | ETypeRecord::IndentColon(p)
@@ -1394,6 +1400,7 @@ pub enum ETypeAbilityImpl<'a> {
 
     Prefix(Position),
     QuestionMark(Position),
+    SecondQuestionMark(Position),
     Ampersand(Position),
     Expr(&'a EExpr<'a>, Position),
     IndentBar(Position),
@@ -1416,6 +1423,7 @@ impl<'a> ETypeAbilityImpl<'a> {
             | ETypeAbilityImpl::Space(_, p)
             | ETypeAbilityImpl::Prefix(p)
             | ETypeAbilityImpl::QuestionMark(p)
+            | ETypeAbilityImpl::SecondQuestionMark(p)
             | ETypeAbilityImpl::Ampersand(p)
             | ETypeAbilityImpl::IndentBar(p)
             | ETypeAbilityImpl::IndentAmpersand(p) => Region::from_pos(*p),
@@ -1435,6 +1443,7 @@ impl<'a> From<ERecord<'a>> for ETypeAbilityImpl<'a> {
             ERecord::Space(s, p) => ETypeAbilityImpl::Space(s, p),
             ERecord::Prefix(p) => ETypeAbilityImpl::Prefix(p),
             ERecord::QuestionMark(p) => ETypeAbilityImpl::QuestionMark(p),
+            ERecord::SecondQuestionMark(p) => ETypeAbilityImpl::SecondQuestionMark(p),
             ERecord::Ampersand(p) => ETypeAbilityImpl::Ampersand(p),
             ERecord::Expr(e, p) => ETypeAbilityImpl::Expr(e, p),
         }
diff --git a/crates/compiler/parse/src/pattern.rs b/crates/compiler/parse/src/pattern.rs
index 5d590038dd9..e94ac3cf124 100644
--- a/crates/compiler/parse/src/pattern.rs
+++ b/crates/compiler/parse/src/pattern.rs
@@ -5,7 +5,7 @@ use crate::blankspace::{space0_before_optional_after, space0_e, spaces, spaces_b
 use crate::ident::{lowercase_ident, parse_ident, Accessor, Ident};
 use crate::keyword;
 use crate::parser::{
-    self, backtrackable, byte, collection_trailing_sep_e, fail_when, loc, map, map_with_arena,
+    self, and, backtrackable, byte, collection_trailing_sep_e, fail_when, loc, map, map_with_arena,
     optional, skip_first, skip_second, specialize_err, specialize_err_ref, then, three_bytes,
     two_bytes, zero_or_more, EPattern, PInParens, PList, PRecord, Parser,
 };
@@ -551,7 +551,10 @@ fn record_pattern_field<'a>() -> impl Parser<'a, Loc<Pattern<'a>>, PRecord<'a>>
         // (This is true in both literals and types.)
         let (_, opt_loc_val, state) = optional(either(
             byte(b':', PRecord::Colon),
-            byte(b'?', PRecord::Optional),
+            and(
+                byte(b'?', PRecord::OptionalFirst),
+                optional(byte(b'?', PRecord::OptionalSecond)),
+            ),
         ))
         .parse(arena, state, min_indent)?;
 
diff --git a/crates/compiler/parse/src/type_annotation.rs b/crates/compiler/parse/src/type_annotation.rs
index ead88c358dd..59deeb859d7 100644
--- a/crates/compiler/parse/src/type_annotation.rs
+++ b/crates/compiler/parse/src/type_annotation.rs
@@ -588,7 +588,10 @@ fn record_type_field<'a>() -> impl Parser<'a, AssignedField<'a, TypeAnnotation<'
         // (This is true in both literals and types.)
         let (_, opt_loc_val, state) = optional(either(
             byte(b':', ETypeRecord::Colon),
-            byte(b'?', ETypeRecord::Optional),
+            and(
+                byte(b'?', ETypeRecord::OptionalFirst),
+                optional(byte(b'?', ETypeRecord::OptionalSecond)),
+            ),
         ))
         .parse(arena, state, min_indent)?;
 
diff --git a/crates/compiler/test_syntax/src/minimize.rs b/crates/compiler/test_syntax/src/minimize.rs
index 6bbe2fd602b..19b7e16ceed 100644
--- a/crates/compiler/test_syntax/src/minimize.rs
+++ b/crates/compiler/test_syntax/src/minimize.rs
@@ -102,10 +102,7 @@ fn round_trip_once(input: Input<'_>, options: Options) -> Option<String> {
     let arena = Bump::new();
 
     let actual = match input.parse_in(&arena) {
-        Ok(a) => {
-            println!("actual {a:#?}");
-            a
-        }
+        Ok(a) => a,
         Err(e) => {
             if options.minimize_initial_parse_error {
                 return Some(format!("Initial parse failed: {:?}", e.normalize(&arena)));
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/closure_complex_pattern_indent_issue.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/closure_complex_pattern_indent_issue.expr.formatted.roc
index 4a4be5405e0..540a97f970a 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/closure_complex_pattern_indent_issue.expr.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/closure_complex_pattern_indent_issue.expr.formatted.roc
@@ -1,3 +1,3 @@
-\I { p ? Y
+\I { p ?? Y
     Y } [] ->
         K # (
\ No newline at end of file
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/if_in_record_field_opt_pat.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/if_in_record_field_opt_pat.expr.formatted.roc
index a5817a11d52..81fc55f32e7 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/if_in_record_field_opt_pat.expr.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/if_in_record_field_opt_pat.expr.formatted.roc
@@ -1,5 +1,5 @@
 O
-    { p ? if
+    { p ?? if
         a
     then
         A
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/module_with_optional_param.header.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/module_with_optional_param.header.formatted.roc
index d3d39f28a6f..e9f8a6bc20e 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/module_with_optional_param.header.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/module_with_optional_param.header.formatted.roc
@@ -1 +1 @@
-module { x, y ? 0 } -> [menu]
+module { x, y ?? 0 } -> [menu]
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/multiline_str_opt_field.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/multiline_str_opt_field.expr.formatted.roc
index 0e7ecd88b96..652cd0cd72c 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/multiline_str_opt_field.expr.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/multiline_str_opt_field.expr.formatted.roc
@@ -1,5 +1,5 @@
 {
-    l?
+    l??
     """
     """,
 }
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/newline_after_opt_field.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/newline_after_opt_field.expr.formatted.roc
index ddca639ed19..cd981a8c14b 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/newline_after_opt_field.expr.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/newline_after_opt_field.expr.formatted.roc
@@ -1,3 +1,3 @@
 {
-    i? p,
+    i?? p,
 }
\ No newline at end of file
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_pat.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_pat.expr.formatted.roc
index 45bbf90e78a..e891f92d1a7 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_pat.expr.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_pat.expr.formatted.roc
@@ -1,2 +1,2 @@
-{ i ? Y } = p
+{ i ?? Y } = p
 Q
\ No newline at end of file
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_ty.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_ty.expr.formatted.roc
index 058df007df3..d2325d77874 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_ty.expr.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_ty.expr.formatted.roc
@@ -1,5 +1,5 @@
 0 : {
     i
-    ? d,
+    ?? d,
 }
 O
\ No newline at end of file
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/opt_record_field_pat_assign.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/opt_record_field_pat_assign.expr.formatted.roc
index fb811c1ffa8..017dc723a0b 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/opt_record_field_pat_assign.expr.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/opt_record_field_pat_assign.expr.formatted.roc
@@ -1,4 +1,4 @@
-{ e ? f
+{ e ?? f
     4 } = f
         e
 r
\ No newline at end of file
diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/pattern_opt_field_bonanza.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/pattern_opt_field_bonanza.expr.formatted.roc
index 881835923f7..da39c04a1a0 100644
--- a/crates/compiler/test_syntax/tests/snapshots/pass/pattern_opt_field_bonanza.expr.formatted.roc
+++ b/crates/compiler/test_syntax/tests/snapshots/pass/pattern_opt_field_bonanza.expr.formatted.roc
@@ -1,8 +1,8 @@
 M
-    { s ? s
+    { s ?? s
         { J &
         } }
-    { s ? s
+    { s ?? s
         { J &
         } } : p
 y
\ No newline at end of file
diff --git a/crates/compiler/test_syntax/tests/test_fmt.rs b/crates/compiler/test_syntax/tests/test_fmt.rs
index 0abef3660d8..767939ccbd4 100644
--- a/crates/compiler/test_syntax/tests/test_fmt.rs
+++ b/crates/compiler/test_syntax/tests/test_fmt.rs
@@ -2497,13 +2497,13 @@ mod test_fmt {
         expr_formats_to(
             indoc!(
                 r"
-                f : { a ?Str }
+                f : { a ??Str }
 
                 f"
             ),
             indoc!(
                 r"
-                f : { a ? Str }
+                f : { a ?? Str }
 
                 f"
             ),
@@ -2513,7 +2513,7 @@ mod test_fmt {
             indoc!(
                 r"
                 f : {
-                    a ?Str,
+                    a ??Str,
                 }
 
                 f"
@@ -2521,7 +2521,7 @@ mod test_fmt {
             indoc!(
                 r"
                 f : {
-                    a ? Str,
+                    a ?? Str,
                 }
 
                 f"
@@ -2743,7 +2743,7 @@ mod test_fmt {
                 r"
                 f :
                     {
-                        someField ? Int * # comment 1
+                        someField ?? Int * # comment 1
                         ,
                         # comment 2
                     }
@@ -2753,7 +2753,7 @@ mod test_fmt {
             indoc!(
                 r"
                 f : {
-                    some_field ? Int *, # comment 1
+                    some_field ?? Int *, # comment 1
                     # comment 2
                 }
 
diff --git a/crates/reporting/src/error/parse.rs b/crates/reporting/src/error/parse.rs
index 9b9e6689b7c..4784ed0f64f 100644
--- a/crates/reporting/src/error/parse.rs
+++ b/crates/reporting/src/error/parse.rs
@@ -2449,7 +2449,7 @@ fn to_precord_report<'a>(
         PRecord::Colon(_) => {
             unreachable!("because `foo` is a valid field; the colon is not required")
         }
-        PRecord::Optional(_) => {
+        PRecord::OptionalFirst(_) | PRecord::OptionalSecond(_) => {
             unreachable!("because `foo` is a valid field; the question mark is not required")
         }
 
@@ -2889,7 +2889,7 @@ fn to_trecord_report<'a>(
                         alloc.region_with_subregion(lines.convert_region(surroundings), region, severity),
                         alloc.concat([
                             alloc.reflow(
-                                r"I was expecting to see a colon, question mark, comma or closing curly brace.",
+                                r"I was expecting to see a colon, two question marks (??), comma or closing curly brace.",
                             ),
                         ]),
                     ]);
@@ -2976,7 +2976,7 @@ fn to_trecord_report<'a>(
         ETypeRecord::Colon(_) => {
             unreachable!("because `foo` is a valid field; the colon is not required")
         }
-        ETypeRecord::Optional(_) => {
+        ETypeRecord::OptionalFirst(_) | ETypeRecord::OptionalSecond(_) => {
             unreachable!("because `foo` is a valid field; the question mark is not required")
         }
 
diff --git a/docker/devcontainer/Dockerfile b/docker/devcontainer/Dockerfile
new file mode 100644
index 00000000000..3c9aa2d53bd
--- /dev/null
+++ b/docker/devcontainer/Dockerfile
@@ -0,0 +1,31 @@
+# Use the base image for rust
+FROM mcr.microsoft.com/devcontainers/rust:1-1-bullseye
+
+# Install required packages and configure features
+
+# Install packages required by onCreateCommand
+RUN apt-get update && \
+    apt-get install -y pkg-config libz-dev libzstd-dev valgrind
+
+# Install Zig 0.13.0
+ARG ZIG_VERSION=0.13.0
+RUN apt-get update && \
+    apt-get install -y wget curl && \
+    curl -o zig.tar.gz https://ziglang.org/download/${ZIG_VERSION}/zig-linux-x86_64-${ZIG_VERSION}.tar.xz && \
+    tar -xf zig.tar.gz && \
+    mv zig-linux-x86_64-${ZIG_VERSION} /usr/local/zig && \
+    rm zig.tar.gz && \
+    ln -s /usr/local/zig/zig /usr/local/bin/zig && \
+    apt-get remove -y --purge wget curl && \
+    apt-get autoremove -y
+
+# Install LLVM 18
+ARG LLVM_VERSION=18
+RUN apt-get update && \
+    apt-get install -y wget gnupg software-properties-common && \
+    wget https://apt.llvm.org/llvm.sh && \
+    chmod +x llvm.sh && \
+    ./llvm.sh ${LLVM_VERSION} && \
+    rm llvm.sh && \
+    apt-get remove -y --purge wget gnupg software-properties-common && \
+    apt-get autoremove -y
\ No newline at end of file