fix: In POSIX sh, local is undefined

breaking/entrypoint.sh

@@ -1,36 +1,37 @@
 #!/bin/sh
 set -e
 
+readonly base="$1"
+readonly revision="$2"
+readonly fail_on_diff="$3"
+readonly include_checks="$4"
+readonly include_path_params="$5"
+readonly deprecation_days_beta="$6"
+readonly deprecation_days_stable="$7"
+readonly exclude_elements="$8"
+readonly composed="$9"
+readonly output_to_file="$10"
+
 write_output () {
-    local output="$1"
+    _write_output_output="$1"
     if [ -n "$output_to_file" ]; then
-        local file_output="$2"
-        if [ -z "$file_output" ]; then
-            file_output=$output
+        _write_output_file_output="$2"
+        if [ -z "$_write_output_file_output" ]; then
+            _write_output_file_output=$_write_output_output
+
         fi
-        echo "$file_output" >> "$output_to_file"
+        echo "$_write_output_file_output" >> "$output_to_file"
     fi
     # github-action limits output to 1MB
     # we count bytes because unicode has multibyte characters
-    size=$(echo "$output" | wc -c)
+    size=$(echo "$_write_output_output" | wc -c)
     if [ "$size" -ge "1000000" ]; then
         echo "WARN: diff exceeds the 1MB limit, truncating output..." >&2
-        output=$(echo "$output" | head -c 1000000)
+        _write_output_output=$(echo "$_write_output_output" | head -c 1000000)
     fi
-    echo "$output" >>"$GITHUB_OUTPUT"
+    echo "$_write_output_output" >>"$GITHUB_OUTPUT"
 }
 
-readonly base="$1"
-readonly revision="$2"
-readonly fail_on_diff="$3"
-readonly include_checks="$4"
-readonly include_path_params="$5"
-readonly deprecation_days_beta="$6"
-readonly deprecation_days_stable="$7"
-readonly exclude_elements="$8"
-readonly composed="$9"
-readonly output_to_file="${10}"
-
 echo "running oasdiff breaking... base: $base, revision: $revision, fail_on_diff: $fail_on_diff, include_checks: $include_checks, include_path_params: $include_path_params, deprecation_days_beta: $deprecation_days_beta, deprecation_days_stable: $deprecation_days_stable, exclude_elements: $exclude_elements, composed: $composed, output_to_file: $output_to_file"
 
 # Build flags to pass in command