Fix bad warning

CHANGELOG.md

@@ -12,6 +12,10 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
 
 ##### Bug Fixes
 
+* Fix script breaking when attempting to print a warning.  
+  [Igor Makarov](https://github.com/igor-makarov)
+  [#11251](https://github.com/CocoaPods/CocoaPods/issues/11251)
+
 * Do not consider podspec_repo when analying sandbox for changes.  
   [Dimitris Koutsogiorgas](https://github.com/dnkoutso)
   [#10985](https://github.com/CocoaPods/CocoaPods/pull/10985)

lib/cocoapods/generator/copy_xcframework_script.rb

@@ -132,7 +132,7 @@ def script
   select_slice "${basepath}" "${paths[@]}"
   local target_path="$SELECT_SLICE_RETVAL"
   if [[ -z "$target_path" ]]; then
-    echo "warning: [CP] $(basename ${basepath}): Unable to find matching slice in '${paths[@]}' for the current build architectures ($ARCHS) and platform ($EFFECTIVE_PLATFORM_NAME)."
+    echo "warning: [CP] $(basename ${basepath}): Unable to find matching slice in '${paths[@]}' for the current build architectures ($ARCHS) and platform (${EFFECTIVE_PLATFORM_NAME-${PLATFORM_NAME}})."
     return
   fi
   local source="$basepath/$target_path"