fix: strip null bytes from GCC output and handle empty YAML files

lib/ceedling/preprocessinator_extractor.rb

@@ -8,6 +8,7 @@
 require 'ceedling/constants'
 require 'ceedling/encodinator'
 require 'ceedling/parsing_parcels'
+require 'stringio'
 
 class PreprocessinatorExtractor 
 
@@ -80,6 +81,10 @@ class PreprocessinatorExtractor
 
   # `input` must have the interface of IO -- StringIO for testing or File in typical use
   def extract_file_as_array_from_expansion(input, filepath)
+    # Strip null bytes that GCC -E may embed in preprocessed output.
+    # Null bytes cause encoding errors in downstream line processing.
+    content = input.read.to_s.gsub("\0", "")
+    input = StringIO.new(content)
 
     ##
     ## Iterate through all lines and alternate between extract and ignore modes.

lib/ceedling/system_wrapper.rb

@@ -75,6 +75,12 @@ def shell_capture3(command:, boom:false)
 
     stdout, stderr, status = Open3.capture3(command)
 
+    # Strip null bytes that some tools (e.g. GCC -H / -E) may inject into output.
+    # Null bytes cause ArgumentError ("string contains null byte") in downstream
+    # processing such as file path operations and YAML parsing.
+    stdout = stdout.to_s.gsub("\0", "")
+    stderr = stderr.to_s.gsub("\0", "")
+
     # If boom, then capture the actual exit code.
     # Otherwise, leave it as zero as though execution succeeded.
     exit_code = status.exitstatus.freeze if boom and !status.nil?
@@ -87,7 +93,7 @@ def shell_capture3(command:, boom:false)
       output: (stdout + stderr).to_s.freeze, 
 
       # Individual streams for detailed logging
-      stdout: stdout.freeze, #TODO PROBABLY DROP THESE TOO
+      stdout: stdout.freeze,
       stderr: stderr.freeze,
 
       # Relay full Process::Status

lib/ceedling/yaml_wrapper.rb

@@ -14,10 +14,14 @@ class YamlWrapper
   def load(filepath)
     source = ERB.new(File.read(filepath)).result
     begin
-      return YAML.load(source, aliases: true)
+      result = YAML.load(source, aliases: true)
     rescue ArgumentError
-      return YAML.load(source)
+      result = YAML.load(source)
     end
+    # YAML.load("") returns false in Ruby, not nil or [].
+    # Callers typically check `result.nil? || result.empty?` which raises
+    # NoMethodError on false. Return [] for empty/false results instead.
+    result == false ? [] : result
   end
 
   def load_string(source)