src/HOL/Mirabelle/lib/scripts/mirabelle.pl

     my ($name, $settings_str) = ($1, $2 || "");
     $name =~ s/^([a-z])/\U$1/;
     print SETUP_FILE "setup {* Mirabelle_$name.invoke [";
     my $sep = "";
     foreach (split(/,/, $settings_str)) {
-      if (m/\s*(.*)\s*=\s*(.*)\s*/) {
+      if (m/\s*([^=]*)\s*=\s*(.*)\s*/) {
         print SETUP_FILE "$sep(\"$1\", \"$2\")";
         $sep = ", ";
       }
       elsif (m/\s*(.*)\s*/) {
 	print SETUP_FILE "$sep(\"$1\", \"\")";