human
Solve the following python programming problem given the following code:
def check_fortran_mangling(conf) : 
    subr = '
      subroutine foobar()
      return
      end
      subroutine foo_bar()
      return
      end
' 
    main_tmpl = '
      int %s() { return 1.
}
' 
    prog_tmpl = '
      void %(foobar)s(void);
      void %(foo_bar)s(void);
      int main() {
      %(foobar)s();
      %(foo_bar)s();
      return 0;
      }
' 
    conf.start_message ('Checking fortran mangling scheme') 
    old = { 
        
} 
    for k in ['F77_LINKFLAGS', 'LIBS', 'LIBDIR'] : 
        old [k] = copy.deepcopy (conf.env [names]) 
try : 
        mangling_lib = 'check_fc_mangling_lib' 
        ret = conf.builders ['fortran'].try_static_library (mangling_lib, subr) 
        if ret : 
            if (conf.env [FC_DUMMY_MAIN] is not None) : 
                main = (main_tmpl % conf.env ['FC_DUMMY_MAIN']) 
else : 
                main = '' 
conf.env ['LIBS'].insert (0, mangling_lib) 
            libdir = conf.last_task.outputs [(- 1)].parent.abspath () 
            conf.env ['LIBDIR'].insert (0, libdir) 
            for (u, du, case) in mangling_generator () : 
                names = { 
                    'foobar' : mangle_func ('foobar', u, du, case), 
                    'foo_bar' : mangle_func ('foo_bar', u, du, case), 
} 
                prog = (prog_tmpl % names) 
                name = 'check_fc_mangling_main' 
                def _name(u) : 
                    if (u == '_') : 
                        return 'u' 
else : 
                        return 'nu' 
name += ('_%s_%s_%s' % (_name (u), _name (du), case)) 
                ret = conf.builders ['ctasks'].try_program (name, (main + prog)) 
                if ret : 
                    conf.env ['FC_MANGLING'] = (u, du, case) 
                    conf.end_message (('%r %r %r' % (u, du, case))) 
                    return 
conf.end_message ('failed !') 
            conf.fail_configuration (None) 
else : 
            conf.end_message ('failed !') 
            conf.fail_configuration (None) 
finally : 
        for k in old : 
           ...

    
    

    Fix the buggy line: old [k] = copy.deepcopy (conf.env [names])
assistant
#Here is Python program to fix the buggy line: old [k] = copy.

old [k] = copy.deepcopy (conf.env [k])