+ return prefix/mid/fn;
+}
+
+void InstalledFile::set_symlink(const FS::Path &l)
+{
+ FS::Path al = FS::dirname(path)/l;
+ if(al==path)
+ throw invalid_argument("InstalledFile::set_symlink");
+ link = FS::dirname(path)/l;
+ builder.get_vfs().register_path(link, this);