diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 4dd7fb9b..1df6f23c 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -29,8 +29,8 @@ jobs:
   test:
     strategy:
       matrix:
-        os: [macos-latest, ubuntu-latest, windows-latest]
-        ruby-version: ['3.1', '3.2', '3.3']
+        os: [macos-latest, ubuntu-latest]
+        ruby-version: ['3.1', '3.2', '3.3', '3.4']
 
     runs-on: ${{ matrix.os }}
     env:
diff --git a/.ruby-version b/.ruby-version
index 15a27998..6cb9d3dd 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.3.0
+3.4.3
diff --git a/Gemfile.lock b/Gemfile.lock
index 01136d57..9a4fcf79 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -8,19 +8,19 @@ GEM
   remote: https://rubygems.org/
   specs:
     ansi (1.5.0)
-    ast (2.4.2)
-    benchmark (0.4.0)
+    ast (2.4.3)
+    benchmark (0.4.1)
     builder (3.3.0)
-    byebug (11.1.3)
-    cli-ui (2.3.0)
+    byebug (12.0.0)
+    cli-ui (2.3.1)
     docile (1.4.1)
     erubi (1.13.1)
-    json (2.10.1)
-    language_server-protocol (3.17.0.4)
+    json (2.13.2)
+    language_server-protocol (3.17.0.5)
     lint_roller (1.1.0)
-    logger (1.6.6)
+    logger (1.7.0)
     method_source (1.1.0)
-    minitest (5.25.4)
+    minitest (5.25.5)
     minitest-reporters (1.7.1)
       ansi
       builder
@@ -29,22 +29,22 @@ GEM
     mocha (2.4.5)
       ruby2_keywords (>= 0.0.5)
     netrc (0.11.0)
-    parallel (1.26.3)
-    parser (3.3.7.1)
+    parallel (1.27.0)
+    parser (3.3.9.0)
       ast (~> 2.4.1)
       racc
-    prism (1.3.0)
+    prism (1.4.0)
     racc (1.8.1)
     rainbow (3.1.1)
-    rake (13.2.1)
-    rbi (0.3.0)
+    rake (13.3.0)
+    rbi (0.3.6)
       prism (~> 1.0)
       rbs (>= 3.4.4)
-      sorbet-runtime (>= 0.5.9204)
-    rbs (3.8.1)
+    rbs (3.9.4)
       logger
     regexp_parser (2.10.0)
-    rubocop (1.73.2)
+    rexml (3.4.1)
+    rubocop (1.79.0)
       json (~> 2.3)
       language_server-protocol (~> 3.17.0.2)
       lint_roller (~> 1.1.0)
@@ -52,39 +52,43 @@ GEM
       parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 2.9.3, < 3.0)
-      rubocop-ast (>= 1.38.0, < 2.0)
+      rubocop-ast (>= 1.46.0, < 2.0)
       ruby-progressbar (~> 1.7)
+      tsort (>= 0.2.0)
       unicode-display_width (>= 2.4.0, < 4.0)
-    rubocop-ast (1.38.1)
-      parser (>= 3.3.1.0)
+    rubocop-ast (1.46.0)
+      parser (>= 3.3.7.2)
+      prism (~> 1.4)
     rubocop-rake (0.7.1)
       lint_roller (~> 1.1)
       rubocop (>= 1.72.1)
-    rubocop-shopify (2.16.0)
+    rubocop-shopify (2.17.1)
       rubocop (~> 1.62)
-    rubocop-sorbet (0.9.0)
-      lint_roller (~> 1.1)
-      rubocop (>= 1)
+    rubocop-sorbet (0.10.5)
+      lint_roller
+      rubocop (>= 1.75.2)
     ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)
     simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.13.1)
+    simplecov-html (0.13.2)
     simplecov_json_formatter (0.1.4)
-    sorbet (0.5.11915)
-      sorbet-static (= 0.5.11915)
-    sorbet-runtime (0.5.11915)
-    sorbet-static (0.5.11915-universal-darwin)
-    sorbet-static (0.5.11915-x86_64-linux)
-    sorbet-static-and-runtime (0.5.11915)
-      sorbet (= 0.5.11915)
-      sorbet-runtime (= 0.5.11915)
-    spoom (1.5.4)
+    sorbet (0.5.12358)
+      sorbet-static (= 0.5.12358)
+    sorbet-runtime (0.5.12358)
+    sorbet-static (0.5.12358-aarch64-linux)
+    sorbet-static (0.5.12358-universal-darwin)
+    sorbet-static (0.5.12358-x86_64-linux)
+    sorbet-static-and-runtime (0.5.12358)
+      sorbet (= 0.5.12358)
+      sorbet-runtime (= 0.5.12358)
+    spoom (1.6.3)
       erubi (>= 1.10.0)
       prism (>= 0.28.0)
-      rbi (>= 0.2.3)
+      rbi (>= 0.3.3)
+      rexml (>= 3.2.6)
       sorbet-static-and-runtime (>= 0.5.10187)
       thor (>= 0.19.2)
     tapioca (0.16.11)
@@ -97,7 +101,8 @@ GEM
       spoom (>= 1.2.0)
       thor (>= 1.2.0)
       yard-sorbet
-    thor (1.3.2)
+    thor (1.4.0)
+    tsort (0.2.0)
     unicode-display_width (3.1.4)
       unicode-emoji (~> 4.0, >= 4.0.4)
     unicode-emoji (4.0.4)
@@ -107,10 +112,8 @@ GEM
       yard
 
 PLATFORMS
-  arm64-darwin-21
+  aarch64-linux
   universal-darwin
-  x64-mingw-ucrt
-  x64-mingw32
   x86_64-linux
 
 DEPENDENCIES
@@ -132,4 +135,4 @@ DEPENDENCIES
   tapioca
 
 BUNDLED WITH
-   2.4.9
+   2.6.7
diff --git a/dev.yml b/dev.yml
index 491ca41d..56b23c7c 100644
--- a/dev.yml
+++ b/dev.yml
@@ -1,5 +1,7 @@
+nix: true
+
 up:
-  - homebrew:
+  - packages:
       - fswatch
   - ruby
   - bundler
diff --git a/lib/cli/kit/args/evaluation.rb b/lib/cli/kit/args/evaluation.rb
index e74bb772..ef6ce2ca 100644
--- a/lib/cli/kit/args/evaluation.rb
+++ b/lib/cli/kit/args/evaluation.rb
@@ -205,7 +205,7 @@ def lookup_option(opt)
           )
           matches = opts.select { |node| (opt.short && node.name == opt.short) || (opt.long && node.name == opt.long) }
           if (last = matches.last)
-            return(opt.multi? ? matches.map(&:value) : last.value)
+            return (opt.multi? ? matches.map(&:value) : last.value)
           end
 
           opt.default
diff --git a/lib/cli/kit/command_help.rb b/lib/cli/kit/command_help.rb
index cf691553..7ee02eff 100644
--- a/lib/cli/kit/command_help.rb
+++ b/lib/cli/kit/command_help.rb
@@ -135,7 +135,7 @@ def opts_class
         sig { returns(T.nilable(String)) }
         def build_options
           opts = opts_class
-          return(nil) unless opts
+          return unless opts
 
           methods = []
           loop do
diff --git a/lib/cli/kit/error_handler.rb b/lib/cli/kit/error_handler.rb
index 5f59bf10..a591b17f 100644
--- a/lib/cli/kit/error_handler.rb
+++ b/lib/cli/kit/error_handler.rb
@@ -133,9 +133,9 @@ def triage_all_exceptions(&block)
       sig { params(error: T.nilable(Exception)).returns(T.nilable(Exception)) }
       def exception_for_submission(error)
         # happens on normal non-error termination
-        return(nil) if error.nil?
+        return if error.nil?
 
-        return(nil) unless error.bug?
+        return unless error.bug?
 
         case error
         when SignalException
diff --git a/lib/cli/kit/opts.rb b/lib/cli/kit/opts.rb
index e7c163c6..18b50d98 100644
--- a/lib/cli/kit/opts.rb
+++ b/lib/cli/kit/opts.rb
@@ -180,6 +180,13 @@ def rest(name: infer_name, desc: nil)
 
         private
 
+        sig { params(label: T.nilable(String)).returns(T.nilable(Symbol)) }
+        def symbolize(label)
+          return if label.nil?
+
+          label.split('#').last&.to_sym
+        end
+
         sig { returns(Symbol) }
         def infer_name
           to_skip = 1
@@ -190,7 +197,7 @@ def infer_name
               to_skip -= 1
               next
             end
-            return(T.must(loc.label&.to_sym))
+            return T.must(symbolize(loc.label))
           end
           raise(ArgumentError, 'could not infer name')
         end
@@ -218,7 +225,7 @@ def unparsed
         ).returns(T.untyped)
       end
       def each_option(&block)
-        return(enum_for(:each_option)) unless block_given?
+        return enum_for(:each_option) unless block_given?
 
         obj = assert_result!
         obj.defn.options.each do |opt|
@@ -236,7 +243,7 @@ def each_option(&block)
         ).returns(T.untyped)
       end
       def each_flag(&block)
-        return(enum_for(:each_flag)) unless block_given?
+        return enum_for(:each_flag) unless block_given?
 
         obj = assert_result!
         obj.defn.flags.each do |flag|
diff --git a/test/cli/kit/parse_args_test.rb b/test/cli/kit/parse_args_test.rb
index 7014eb3a..e07b83d8 100644
--- a/test/cli/kit/parse_args_test.rb
+++ b/test/cli/kit/parse_args_test.rb
@@ -101,7 +101,6 @@ def test_options_long
       end
 
       def test_options_multi
-        # rubocop:disable Layout/LineLength
         @cmd.call(
           '--maybe --choice --count 100 --sum 111 --val bar --str baz --opt other_val --snake-squad-alpha cobras --count 200 --opt france --opt',
         )
diff --git a/test/cli/kit/support/test_helper_test.rb b/test/cli/kit/support/test_helper_test.rb
index e6adc6de..02e073c3 100644
--- a/test/cli/kit/support/test_helper_test.rb
+++ b/test/cli/kit/support/test_helper_test.rb
@@ -34,8 +34,9 @@ def test_when_commands_not_run_correctly
           CLI::Kit::System.fake('banana', success: true)
           CLI::Kit::System.fake('kiwi', success: true)
 
-          CLI::Kit::System.system('banana', sudo: true, env: { kiwi: false })
-          CLI::Kit::System.system('kiwi', sudo: true, env: { kiwi: false })
+          env = { kiwi: false }
+          CLI::Kit::System.system('banana', sudo: true, env: env)
+          CLI::Kit::System.system('kiwi', sudo: true, env: env)
 
           errors = assert_all_commands_run(should_raise: false)
           expected_err = <<~EOF
@@ -43,11 +44,11 @@ def test_when_commands_not_run_correctly
             Commands were not run as expected:
             banana
             - sudo was supposed to be false but was true
-            - env was supposed to be {} but was {:kiwi=>false}
+            - env was supposed to be {} but was #{env}
 
             kiwi
             - sudo was supposed to be false but was true
-            - env was supposed to be {} but was {:kiwi=>false}
+            - env was supposed to be {} but was #{env}
           EOF
           assert_equal(expected_err, CLI::UI::ANSI.strip_codes(errors))
         end