# Buggy code
def runsource(self, source, filename="<input>", symbol="single"):
    try:
        do = hy_parse(source, filename=filename)
    except PrematureEndOfInput:
        return True
    except HySyntaxError as e:
        self.showsyntaxerror(filename=filename)
        return False

    try:
        # Our compiler doesn't correspond to a real, fixed source file, so
        # we need to [re]set these.
        self.hy_compiler.filename = filename
        self.hy_compiler.source = source
        value = hy_eval(
            do,
            self.locals,
            self.module,
            self.ast_callback,
            compiler=self.hy_compiler,
            filename=filename,
            source=source,
        )
    except SystemExit:
        raise
    except Exception as e:
        self.showtraceback()
        return False

    if value is not None:
        # Shift exisitng REPL results
        next_result = value
        for sym in self._repl_results_symbols:
            self.locals[sym], next_result = next_result, self.locals[sym]

        # Print the value.
        try:
            output = self.output_fn(value)
        except Exception:
            self.showtraceback()
            return False

        print(output)

    return False


# Traceback (hy.errors.HyCompileError)
Traceback (most recent call last):
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/importer.py", line 180, in hy_eval
_ast, expr = hy_compile(hytree, module_name, get_expr=True)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 2213, in hy_compile
result = compiler.compile(tree)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 460, in compile
ret = self.compile_atom(_type, tree)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 447, in compile_atom
else _compile_table[atom_type](self, atom))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 1731, in compile_expression
ret = self.compile_atom(fn, expression)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 447, in compile_atom
else _compile_table[atom_type](self, atom))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 819, in compile_do
return self._compile_branch(expression)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 545, in _compile_branch
return _branch(self.compile(expr) for expr in exprs)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 318, in _branch
results = list(results)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 545, in <genexpr>
return _branch(self.compile(expr) for expr in exprs)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 460, in compile
ret = self.compile_atom(_type, tree)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 447, in compile_atom
else _compile_table[atom_type](self, atom))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 1731, in compile_expression
ret = self.compile_atom(fn, expression)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 447, in compile_atom
else _compile_table[atom_type](self, atom))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 372, in checker
return fn(self, expression)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 873, in compile_try_expression
name)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 1002, in _compile_catch_expression
body = self._compile_branch(expr)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 545, in _compile_branch
return _branch(self.compile(expr) for expr in exprs)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 318, in _branch
results = list(results)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 545, in <genexpr>
return _branch(self.compile(expr) for expr in exprs)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 460, in compile
ret = self.compile_atom(_type, tree)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 447, in compile_atom
else _compile_table[atom_type](self, atom))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 1731, in compile_expression
ret = self.compile_atom(fn, expression)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 447, in compile_atom
else _compile_table[atom_type](self, atom))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 372, in checker
return fn(self, expression)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 858, in compile_try_expression
body += self.compile(expr.pop(0))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 472, in compile
raise_empty(HyCompileError, e, sys.exc_info()[2])
File "<string>", line 1, in raise_empty
hy.errors.HyCompileError: Internal Compiler Bug 😱
⤷ ImportError: cannot require names: [HySymbol('let')]
Compilation traceback:
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 460, in compile
ret = self.compile_atom(_type, tree)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 447, in compile_atom
else _compile_table[atom_type](self, atom))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 1731, in compile_expression
ret = self.compile_atom(fn, expression)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 447, in compile_atom
else _compile_table[atom_type](self, atom))
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/compiler.py", line 1486, in compile_require
require(module, self.module_name, assignments=assignments)
File "/home/johnzhuang/.virtualenvs/hy/lib/python3.6/site-packages/hy/macros.py", line 106, in require
raise ImportError("cannot require names: " + repr(list(unseen)))

# Fixed code
def runsource(self, source, filename="<stdin>", symbol="exec"):
    try:
        res = super(HyREPL, self).runsource(source, filename, symbol)
    except (HyMacroExpansionError, HyRequireError):
        # We need to handle these exceptions ourselves, because the base
        # method only handles `OverflowError`, `SyntaxError` and
        # `ValueError`.
        self.showsyntaxerror(filename)
        return False
    except HyLanguageError:
        # Our compiler will also raise `TypeError`s
        self.showtraceback()
        return False

    # Shift exisitng REPL results
    if not res:
        next_result = self.last_value
        for sym in self._repl_results_symbols:
            self.locals[sym], next_result = next_result, self.locals[sym]

        # Print the value.
        if self.print_last_value:
            try:
                output = self.output_fn(self.last_value)
            except Exception:
                self.showtraceback()
                return False

            print(output)

    return res