diff --git a/lib/docs/wasm/Decl.zig b/lib/docs/wasm/Decl.zig
index ba1a7b455a..79a55294d2 100644
--- a/lib/docs/wasm/Decl.zig
+++ b/lib/docs/wasm/Decl.zig
@@ -6,6 +6,7 @@ const gpa = std.heap.wasm_allocator;
 const assert = std.debug.assert;
 const log = std.log;
 const Oom = error{OutOfMemory};
+const ArrayList = std.ArrayList;
 
 ast_node: Ast.Node.Index,
 file: Walk.File.Index,
@@ -189,7 +190,7 @@ pub fn lookup(decl: *const Decl, name: []const u8) ?Decl.Index {
 }
 
 /// Appends the fully qualified name to `out`.
-pub fn fqn(decl: *const Decl, out: *std.ArrayListUnmanaged(u8)) Oom!void {
+pub fn fqn(decl: *const Decl, out: *ArrayList(u8)) Oom!void {
     try decl.append_path(out);
     if (decl.parent != .none) {
         try append_parent_ns(out, decl.parent);
@@ -199,12 +200,12 @@ pub fn fqn(decl: *const Decl, out: *std.ArrayListUnmanaged(u8)) Oom!void {
     }
 }
 
-pub fn reset_with_path(decl: *const Decl, list: *std.ArrayListUnmanaged(u8)) Oom!void {
+pub fn reset_with_path(decl: *const Decl, list: *ArrayList(u8)) Oom!void {
     list.clearRetainingCapacity();
     try append_path(decl, list);
 }
 
-pub fn append_path(decl: *const Decl, list: *std.ArrayListUnmanaged(u8)) Oom!void {
+pub fn append_path(decl: *const Decl, list: *ArrayList(u8)) Oom!void {
     const start = list.items.len;
     // Prefer the module name alias.
     for (Walk.modules.keys(), Walk.modules.values()) |pkg_name, pkg_file| {
@@ -230,7 +231,7 @@ pub fn append_path(decl: *const Decl, list: *std.ArrayListUnmanaged(u8)) Oom!voi
     }
 }
 
-pub fn append_parent_ns(list: *std.ArrayListUnmanaged(u8), parent: Decl.Index) Oom!void {
+pub fn append_parent_ns(list: *ArrayList(u8), parent: Decl.Index) Oom!void {
     assert(parent != .none);
     const decl = parent.get();
     if (decl.parent != .none) {
diff --git a/lib/docs/wasm/html_render.zig b/lib/docs/wasm/html_render.zig
index 68b10a01e4..13d2ec05c5 100644
--- a/lib/docs/wasm/html_render.zig
+++ b/lib/docs/wasm/html_render.zig
@@ -1,6 +1,8 @@
 const std = @import("std");
 const Ast = std.zig.Ast;
 const assert = std.debug.assert;
+const ArrayList = std.ArrayList;
+const Writer = std.Io.Writer;
 
 const Walk = @import("Walk");
 const Decl = Walk.Decl;
@@ -30,7 +32,7 @@ pub const Annotation = struct {
 
 pub fn fileSourceHtml(
     file_index: Walk.File.Index,
-    out: *std.ArrayListUnmanaged(u8),
+    out: *ArrayList(u8),
     root_node: Ast.Node.Index,
     options: RenderSourceOptions,
 ) !void {
@@ -38,7 +40,7 @@ pub fn fileSourceHtml(
     const file = file_index.get();
 
     const g = struct {
-        var field_access_buffer: std.ArrayListUnmanaged(u8) = .empty;
+        var field_access_buffer: ArrayList(u8) = .empty;
     };
 
     const start_token = ast.firstToken(root_node);
@@ -88,7 +90,7 @@ pub fn fileSourceHtml(
             if (next_annotate_index >= options.source_location_annotations.len) break;
             const next_annotation = options.source_location_annotations[next_annotate_index];
             if (cursor <= next_annotation.file_byte_offset) break;
-            try out.writer(gpa).print("<span id=\"{s}{d}\"></span>", .{
+            try out.print(gpa, "<span id=\"{s}{d}\"></span>", .{
                 options.annotation_prefix, next_annotation.dom_id,
             });
             next_annotate_index += 1;
@@ -318,7 +320,7 @@ pub fn fileSourceHtml(
     }
 }
 
-fn appendUnindented(out: *std.ArrayListUnmanaged(u8), s: []const u8, indent: usize) !void {
+fn appendUnindented(out: *ArrayList(u8), s: []const u8, indent: usize) !void {
     var it = std.mem.splitScalar(u8, s, '\n');
     var is_first_line = true;
     while (it.next()) |line| {
@@ -332,7 +334,7 @@ fn appendUnindented(out: *std.ArrayListUnmanaged(u8), s: []const u8, indent: usi
     }
 }
 
-pub fn appendEscaped(out: *std.ArrayListUnmanaged(u8), s: []const u8) !void {
+pub fn appendEscaped(out: *ArrayList(u8), s: []const u8) !void {
     for (s) |c| {
         try out.ensureUnusedCapacity(gpa, 6);
         switch (c) {
@@ -347,7 +349,7 @@ pub fn appendEscaped(out: *std.ArrayListUnmanaged(u8), s: []const u8) !void {
 
 fn walkFieldAccesses(
     file_index: Walk.File.Index,
-    out: *std.ArrayListUnmanaged(u8),
+    out: *ArrayList(u8),
     node: Ast.Node.Index,
 ) Oom!void {
     const ast = file_index.get_ast();
@@ -371,7 +373,7 @@ fn walkFieldAccesses(
 
 fn resolveIdentLink(
     file_index: Walk.File.Index,
-    out: *std.ArrayListUnmanaged(u8),
+    out: *ArrayList(u8),
     ident_token: Ast.TokenIndex,
 ) Oom!void {
     const decl_index = file_index.get().lookup_token(ident_token);
@@ -391,7 +393,7 @@ fn unindent(s: []const u8, indent: usize) []const u8 {
     return s[indent_idx..];
 }
 
-pub fn resolveDeclLink(decl_index: Decl.Index, out: *std.ArrayListUnmanaged(u8)) Oom!void {
+pub fn resolveDeclLink(decl_index: Decl.Index, out: *ArrayList(u8)) Oom!void {
     const decl = decl_index.get();
     switch (decl.categorize()) {
         .alias => |alias_decl| try alias_decl.get().fqn(out),
diff --git a/lib/docs/wasm/main.zig b/lib/docs/wasm/main.zig
index d3043cd917..adf3f6b884 100644
--- a/lib/docs/wasm/main.zig
+++ b/lib/docs/wasm/main.zig
@@ -5,6 +5,8 @@ const Ast = std.zig.Ast;
 const Walk = @import("Walk");
 const markdown = @import("markdown.zig");
 const Decl = Walk.Decl;
+const ArrayList = std.ArrayList;
+const Writer = std.Io.Writer;
 
 const fileSourceHtml = @import("html_render.zig").fileSourceHtml;
 const appendEscaped = @import("html_render.zig").appendEscaped;
@@ -66,8 +68,8 @@ export fn unpack(tar_ptr: [*]u8, tar_len: usize) void {
     };
 }
 
-var query_string: std.ArrayListUnmanaged(u8) = .empty;
-var query_results: std.ArrayListUnmanaged(Decl.Index) = .empty;
+var query_string: ArrayList(u8) = .empty;
+var query_results: ArrayList(Decl.Index) = .empty;
 
 /// Resizes the query string to be the correct length; returns the pointer to
 /// the query string.
@@ -99,11 +101,11 @@ fn query_exec_fallible(query: []const u8, ignore_case: bool) !void {
         segments: u16,
     };
     const g = struct {
-        var full_path_search_text: std.ArrayListUnmanaged(u8) = .empty;
-        var full_path_search_text_lower: std.ArrayListUnmanaged(u8) = .empty;
-        var doc_search_text: std.ArrayListUnmanaged(u8) = .empty;
+        var full_path_search_text: ArrayList(u8) = .empty;
+        var full_path_search_text_lower: ArrayList(u8) = .empty;
+        var doc_search_text: ArrayList(u8) = .empty;
         /// Each element matches a corresponding query_results element.
-        var scores: std.ArrayListUnmanaged(Score) = .empty;
+        var scores: ArrayList(Score) = .empty;
     };
 
     // First element stores the size of the list.
@@ -234,7 +236,7 @@ const ErrorIdentifier = packed struct(u64) {
         return ast.tokenTag(token_index - 1) == .doc_comment;
     }
 
-    fn html(ei: ErrorIdentifier, base_decl: Decl.Index, out: *std.ArrayListUnmanaged(u8)) Oom!void {
+    fn html(ei: ErrorIdentifier, base_decl: Decl.Index, out: *ArrayList(u8)) Oom!void {
         const decl_index = ei.decl_index;
         const ast = decl_index.get().file.get_ast();
         const name = ast.tokenSlice(ei.token_index);
@@ -260,7 +262,7 @@ const ErrorIdentifier = packed struct(u64) {
     }
 };
 
-var string_result: std.ArrayListUnmanaged(u8) = .empty;
+var string_result: ArrayList(u8) = .empty;
 var error_set_result: std.StringArrayHashMapUnmanaged(ErrorIdentifier) = .empty;
 
 export fn decl_error_set(decl_index: Decl.Index) Slice(ErrorIdentifier) {
@@ -411,7 +413,7 @@ fn decl_fields_fallible(decl_index: Decl.Index) ![]Ast.Node.Index {
 
 fn ast_decl_fields_fallible(ast: *Ast, ast_index: Ast.Node.Index) ![]Ast.Node.Index {
     const g = struct {
-        var result: std.ArrayListUnmanaged(Ast.Node.Index) = .empty;
+        var result: ArrayList(Ast.Node.Index) = .empty;
     };
     g.result.clearRetainingCapacity();
     var buf: [2]Ast.Node.Index = undefined;
@@ -429,7 +431,7 @@ fn ast_decl_fields_fallible(ast: *Ast, ast_index: Ast.Node.Index) ![]Ast.Node.In
 
 fn decl_params_fallible(decl_index: Decl.Index) ![]Ast.Node.Index {
     const g = struct {
-        var result: std.ArrayListUnmanaged(Ast.Node.Index) = .empty;
+        var result: ArrayList(Ast.Node.Index) = .empty;
     };
     g.result.clearRetainingCapacity();
     const decl = decl_index.get();
@@ -460,7 +462,7 @@ export fn decl_param_html(decl_index: Decl.Index, param_node: Ast.Node.Index) St
 }
 
 fn decl_field_html_fallible(
-    out: *std.ArrayListUnmanaged(u8),
+    out: *ArrayList(u8),
     decl_index: Decl.Index,
     field_node: Ast.Node.Index,
 ) !void {
@@ -480,7 +482,7 @@ fn decl_field_html_fallible(
 }
 
 fn decl_param_html_fallible(
-    out: *std.ArrayListUnmanaged(u8),
+    out: *ArrayList(u8),
     decl_index: Decl.Index,
     param_node: Ast.Node.Index,
 ) !void {
@@ -649,7 +651,7 @@ export fn decl_docs_html(decl_index: Decl.Index, short: bool) String {
 }
 
 fn collect_docs(
-    list: *std.ArrayListUnmanaged(u8),
+    list: *ArrayList(u8),
     ast: *const Ast,
     first_doc_comment: Ast.TokenIndex,
 ) Oom!void {
@@ -667,7 +669,7 @@ fn collect_docs(
 }
 
 fn render_docs(
-    out: *std.ArrayListUnmanaged(u8),
+    out: *ArrayList(u8),
     decl_index: Decl.Index,
     first_doc_comment: Ast.TokenIndex,
     short: bool,
@@ -691,11 +693,10 @@ fn render_docs(
     defer parsed_doc.deinit(gpa);
 
     const g = struct {
-        var link_buffer: std.ArrayListUnmanaged(u8) = .empty;
+        var link_buffer: ArrayList(u8) = .empty;
     };
 
-    const Writer = std.ArrayListUnmanaged(u8).Writer;
-    const Renderer = markdown.Renderer(Writer, Decl.Index);
+    const Renderer = markdown.Renderer(Decl.Index);
     const renderer: Renderer = .{
         .context = decl_index,
         .renderFn = struct {
@@ -703,8 +704,8 @@ fn render_docs(
                 r: Renderer,
                 doc: markdown.Document,
                 node: markdown.Document.Node.Index,
-                writer: Writer,
-            ) !void {
+                writer: *Writer,
+            ) Writer.Error!void {
                 const data = doc.nodes.items(.data)[@intFromEnum(node)];
                 switch (doc.nodes.items(.tag)[@intFromEnum(node)]) {
                     .code_span => {
@@ -712,7 +713,7 @@ fn render_docs(
                         const content = doc.string(data.text.content);
                         if (resolve_decl_path(r.context, content)) |resolved_decl_index| {
                             g.link_buffer.clearRetainingCapacity();
-                            try resolveDeclLink(resolved_decl_index, &g.link_buffer);
+                            resolveDeclLink(resolved_decl_index, &g.link_buffer) catch return error.WriteFailed;
 
                             try writer.writeAll("<a href=\"#");
                             _ = missing_feature_url_escape;
@@ -730,7 +731,12 @@ fn render_docs(
             }
         }.render,
     };
-    try renderer.render(parsed_doc, out.writer(gpa));
+
+    var allocating = Writer.Allocating.fromArrayList(gpa, out);
+    defer out.* = allocating.toArrayList();
+    renderer.render(parsed_doc, &allocating.writer) catch |err| switch (err) {
+        error.WriteFailed => return error.OutOfMemory,
+    };
 }
 
 fn resolve_decl_path(decl_index: Decl.Index, path: []const u8) ?Decl.Index {
@@ -827,7 +833,7 @@ export fn find_module_root(pkg: Walk.ModuleIndex) Decl.Index {
 }
 
 /// Set by `set_input_string`.
-var input_string: std.ArrayListUnmanaged(u8) = .empty;
+var input_string: ArrayList(u8) = .empty;
 
 export fn set_input_string(len: usize) [*]u8 {
     input_string.resize(gpa, len) catch @panic("OOM");
@@ -849,7 +855,7 @@ export fn find_decl() Decl.Index {
     if (result != .none) return result;
 
     const g = struct {
-        var match_fqn: std.ArrayListUnmanaged(u8) = .empty;
+        var match_fqn: ArrayList(u8) = .empty;
     };
     for (Walk.decls.items, 0..) |*decl, decl_index| {
         g.match_fqn.clearRetainingCapacity();
@@ -905,7 +911,7 @@ export fn type_fn_members(parent: Decl.Index, include_private: bool) Slice(Decl.
 
 export fn namespace_members(parent: Decl.Index, include_private: bool) Slice(Decl.Index) {
     const g = struct {
-        var members: std.ArrayListUnmanaged(Decl.Index) = .empty;
+        var members: ArrayList(Decl.Index) = .empty;
     };
 
     g.members.clearRetainingCapacity();
diff --git a/lib/docs/wasm/markdown/renderer.zig b/lib/docs/wasm/markdown/renderer.zig
index cba857d204..13e3795b9a 100644
--- a/lib/docs/wasm/markdown/renderer.zig
+++ b/lib/docs/wasm/markdown/renderer.zig
@@ -2,25 +2,26 @@ const std = @import("std");
 const Document = @import("Document.zig");
 const Node = Document.Node;
 const assert = std.debug.assert;
+const Writer = std.Io.Writer;
 
 /// A Markdown document renderer.
 ///
 /// Each concrete `Renderer` type has a `renderDefault` function, with the
 /// intention that custom `renderFn` implementations can call `renderDefault`
 /// for node types for which they require no special rendering.
-pub fn Renderer(comptime Writer: type, comptime Context: type) type {
+pub fn Renderer(comptime Context: type) type {
     return struct {
         renderFn: *const fn (
             r: Self,
             doc: Document,
             node: Node.Index,
-            writer: Writer,
+            writer: *Writer,
         ) Writer.Error!void = renderDefault,
         context: Context,
 
         const Self = @This();
 
-        pub fn render(r: Self, doc: Document, writer: Writer) Writer.Error!void {
+        pub fn render(r: Self, doc: Document, writer: *Writer) Writer.Error!void {
             try r.renderFn(r, doc, .root, writer);
         }
 
@@ -28,7 +29,7 @@ pub fn Renderer(comptime Writer: type, comptime Context: type) type {
             r: Self,
             doc: Document,
             node: Node.Index,
-            writer: Writer,
+            writer: *Writer,
         ) Writer.Error!void {
             const data = doc.nodes.items(.data)[@intFromEnum(node)];
             switch (doc.nodes.items(.tag)[@intFromEnum(node)]) {
@@ -188,8 +189,8 @@ pub fn Renderer(comptime Writer: type, comptime Context: type) type {
 pub fn renderInlineNodeText(
     doc: Document,
     node: Node.Index,
-    writer: anytype,
-) @TypeOf(writer).Error!void {
+    writer: *Writer,
+) Writer.Error!void {
     const data = doc.nodes.items(.data)[@intFromEnum(node)];
     switch (doc.nodes.items(.tag)[@intFromEnum(node)]) {
         .root,
@@ -234,14 +235,12 @@ pub fn fmtHtml(bytes: []const u8) std.fmt.Formatter([]const u8, formatHtml) {
     return .{ .data = bytes };
 }
 
-fn formatHtml(bytes: []const u8, writer: *std.io.Writer) std.io.Writer.Error!void {
-    for (bytes) |b| {
-        switch (b) {
-            '<' => try writer.writeAll("&lt;"),
-            '>' => try writer.writeAll("&gt;"),
-            '&' => try writer.writeAll("&amp;"),
-            '"' => try writer.writeAll("&quot;"),
-            else => try writer.writeByte(b),
-        }
-    }
+fn formatHtml(bytes: []const u8, w: *Writer) Writer.Error!void {
+    for (bytes) |b| switch (b) {
+        '<' => try w.writeAll("&lt;"),
+        '>' => try w.writeAll("&gt;"),
+        '&' => try w.writeAll("&amp;"),
+        '"' => try w.writeAll("&quot;"),
+        else => try w.writeByte(b),
+    };
 }
diff --git a/tools/docgen.zig b/tools/docgen.zig
index 04066eff78..fbab24576c 100644
--- a/tools/docgen.zig
+++ b/tools/docgen.zig
@@ -1,6 +1,5 @@
 const std = @import("std");
 const builtin = @import("builtin");
-const io = std.io;
 const fs = std.fs;
 const process = std.process;
 const Progress = std.Progress;
@@ -8,8 +7,10 @@ const print = std.debug.print;
 const mem = std.mem;
 const testing = std.testing;
 const Allocator = std.mem.Allocator;
+const ArrayList = std.ArrayList;
 const getExternalExecutor = std.zig.system.getExternalExecutor;
 const fatal = std.process.fatal;
+const Writer = std.Io.Writer;
 
 const max_doc_file_size = 10 * 1024 * 1024;
 
@@ -344,10 +345,10 @@ fn genToc(allocator: Allocator, tokenizer: *Tokenizer) !Toc {
     var last_action: Action = .open;
     var last_columns: ?u8 = null;
 
-    var toc_buf = std.array_list.Managed(u8).init(allocator);
+    var toc_buf: Writer.Allocating = .init(allocator);
     defer toc_buf.deinit();
 
-    var toc = toc_buf.writer();
+    const toc = &toc_buf.writer;
 
     var nodes = std.array_list.Managed(Node).init(allocator);
     defer nodes.deinit();
@@ -422,7 +423,7 @@ fn genToc(allocator: Allocator, tokenizer: *Tokenizer) !Toc {
                     }
                     if (last_action == .open) {
                         try toc.writeByte('\n');
-                        try toc.writeByteNTimes(' ', header_stack_size * 4);
+                        try toc.splatByteAll(' ', header_stack_size * 4);
                         if (last_columns) |n| {
                             try toc.print("<ul style=\"columns: {d}\">\n", .{n});
                         } else {
@@ -432,7 +433,7 @@ fn genToc(allocator: Allocator, tokenizer: *Tokenizer) !Toc {
                         last_action = .open;
                     }
                     last_columns = columns;
-                    try toc.writeByteNTimes(' ', 4 + header_stack_size * 4);
+                    try toc.splatByteAll(' ', 4 + header_stack_size * 4);
                     try toc.print("<li><a id=\"toc-{s}\" href=\"#{s}\">{s}</a>", .{ urlized, urlized, content });
                 } else if (mem.eql(u8, tag_name, "header_close")) {
                     if (header_stack_size == 0) {
@@ -442,7 +443,7 @@ fn genToc(allocator: Allocator, tokenizer: *Tokenizer) !Toc {
                     _ = try eatToken(tokenizer, .bracket_close);
 
                     if (last_action == .close) {
-                        try toc.writeByteNTimes(' ', 8 + header_stack_size * 4);
+                        try toc.splatByteAll(' ', 8 + header_stack_size * 4);
                         try toc.writeAll("</ul></li>\n");
                     } else {
                         try toc.writeAll("</li>\n");
@@ -591,30 +592,29 @@ fn genToc(allocator: Allocator, tokenizer: *Tokenizer) !Toc {
         }
     }
 
-    return Toc{
+    return .{
         .nodes = try nodes.toOwnedSlice(),
         .toc = try toc_buf.toOwnedSlice(),
         .urls = urls,
     };
 }
 
-fn urlize(allocator: Allocator, input: []const u8) ![]u8 {
-    var buf = std.array_list.Managed(u8).init(allocator);
-    defer buf.deinit();
+fn urlize(gpa: Allocator, input: []const u8) ![]u8 {
+    var buf: ArrayList(u8) = .empty;
+    defer buf.deinit(gpa);
 
-    const out = buf.writer();
     for (input) |c| {
         switch (c) {
             'a'...'z', 'A'...'Z', '_', '-', '0'...'9' => {
-                try out.writeByte(c);
+                try buf.append(gpa, c);
             },
             ' ' => {
-                try out.writeByte('-');
+                try buf.append(gpa, '-');
             },
             else => {},
         }
     }
-    return try buf.toOwnedSlice();
+    return try buf.toOwnedSlice(gpa);
 }
 
 fn escapeHtml(allocator: Allocator, input: []const u8) ![]u8 {
@@ -626,7 +626,7 @@ fn escapeHtml(allocator: Allocator, input: []const u8) ![]u8 {
     return try buf.toOwnedSlice();
 }
 
-fn writeEscaped(out: anytype, input: []const u8) !void {
+fn writeEscaped(out: *Writer, input: []const u8) !void {
     for (input) |c| {
         try switch (c) {
             '&' => out.writeAll("&amp;"),
@@ -662,14 +662,14 @@ fn isType(name: []const u8) bool {
     return false;
 }
 
-fn writeEscapedLines(out: anytype, text: []const u8) !void {
+fn writeEscapedLines(out: *Writer, text: []const u8) !void {
     return writeEscaped(out, text);
 }
 
 fn tokenizeAndPrintRaw(
     allocator: Allocator,
     docgen_tokenizer: *Tokenizer,
-    out: anytype,
+    out: *Writer,
     source_token: Token,
     raw_src: []const u8,
 ) !void {
@@ -907,14 +907,14 @@ fn tokenizeAndPrintRaw(
 fn tokenizeAndPrint(
     allocator: Allocator,
     docgen_tokenizer: *Tokenizer,
-    out: anytype,
+    out: *Writer,
     source_token: Token,
 ) !void {
     const raw_src = docgen_tokenizer.buffer[source_token.start..source_token.end];
     return tokenizeAndPrintRaw(allocator, docgen_tokenizer, out, source_token, raw_src);
 }
 
-fn printSourceBlock(allocator: Allocator, docgen_tokenizer: *Tokenizer, out: anytype, syntax_block: SyntaxBlock) !void {
+fn printSourceBlock(allocator: Allocator, docgen_tokenizer: *Tokenizer, out: *Writer, syntax_block: SyntaxBlock) !void {
     const source_type = @tagName(syntax_block.source_type);
 
     try out.print("<figure><figcaption class=\"{s}-cap\"><cite class=\"file\">{s}</cite></figcaption><pre>", .{ source_type, syntax_block.name });
@@ -932,7 +932,7 @@ fn printSourceBlock(allocator: Allocator, docgen_tokenizer: *Tokenizer, out: any
     try out.writeAll("</pre></figure>");
 }
 
-fn printShell(out: anytype, shell_content: []const u8, escape: bool) !void {
+fn printShell(out: *Writer, shell_content: []const u8, escape: bool) !void {
     const trimmed_shell_content = mem.trim(u8, shell_content, " \r\n");
     try out.writeAll("<figure><figcaption class=\"shell-cap\">Shell</figcaption><pre><samp>");
     var cmd_cont: bool = false;
@@ -984,7 +984,7 @@ fn genHtml(
     tokenizer: *Tokenizer,
     toc: *Toc,
     code_dir: std.fs.Dir,
-    out: anytype,
+    out: *Writer,
 ) !void {
     for (toc.nodes) |node| {
         switch (node) {
diff --git a/tools/doctest.zig b/tools/doctest.zig
index 2c8f14e913..9aa7262d7f 100644
--- a/tools/doctest.zig
+++ b/tools/doctest.zig
@@ -127,9 +127,9 @@ fn printOutput(
     const obj_ext = builtin.object_format.fileExt(builtin.cpu.arch);
     const print = std.debug.print;
 
-    var shell_buffer = std.array_list.Managed(u8).init(arena);
+    var shell_buffer: std.Io.Writer.Allocating = .init(arena);
     defer shell_buffer.deinit();
-    var shell_out = shell_buffer.writer();
+    const shell_out = &shell_buffer.writer;
 
     const code_name = std.fs.path.stem(input_path);
 
@@ -600,7 +600,7 @@ fn printOutput(
     }
 
     if (!code.just_check_syntax) {
-        try printShell(out, shell_buffer.items, false);
+        try printShell(out, shell_buffer.written(), false);
     }
 }
 
@@ -975,25 +975,21 @@ fn skipPrefix(line: []const u8) []const u8 {
     return line[3..];
 }
 
-fn escapeHtml(allocator: Allocator, input: []const u8) ![]u8 {
-    var buf = std.array_list.Managed(u8).init(allocator);
-    defer buf.deinit();
-
-    const out = buf.writer();
-    try writeEscaped(out, input);
-    return try buf.toOwnedSlice();
+fn escapeHtml(gpa: Allocator, input: []const u8) ![]u8 {
+    var allocating: Writer.Allocating = .init(gpa);
+    defer allocating.deinit();
+    try writeEscaped(&allocating.writer, input);
+    return allocating.toOwnedSlice();
 }
 
-fn writeEscaped(out: *Writer, input: []const u8) !void {
-    for (input) |c| {
-        try switch (c) {
-            '&' => out.writeAll("&amp;"),
-            '<' => out.writeAll("&lt;"),
-            '>' => out.writeAll("&gt;"),
-            '"' => out.writeAll("&quot;"),
-            else => out.writeByte(c),
-        };
-    }
+fn writeEscaped(w: *Writer, input: []const u8) !void {
+    for (input) |c| try switch (c) {
+        '&' => w.writeAll("&amp;"),
+        '<' => w.writeAll("&lt;"),
+        '>' => w.writeAll("&gt;"),
+        '"' => w.writeAll("&quot;"),
+        else => w.writeByte(c),
+    };
 }
 
 fn termColor(allocator: Allocator, input: []const u8) ![]u8 {