--- a/make/update-rules.sh	Thu May 21 12:07:54 2026 +0200
+++ b/make/update-rules.sh	Thu May 21 12:29:23 2026 +0200
@@ -47,7 +47,7 @@
 sed '/FORCE:/q' Makefile.old > Makefile
 echo >> Makefile
 for file in `ls *.cpp` ; do
-  "$CXX" -MT "$target/${file/.cpp/\.o}" -MM $CXXFLAGS $extra_flags "$file"
+  "$CXX" -MT "$target/${file%.cpp}.o" -MM $CXXFLAGS $extra_flags "$file"
   printf '\t@echo "Compiling $<"\n'
   printf '\t$(CXX) -o $@ $(CXXFLAGS) %s -c $<\n\n' "$extra_flags"
 done  >> Makefile