auto_quote_error2.lean:5:2: error: invalid apply tactic, failed to unify
  a = c
with
  ?m_2 = ?m_2
state:
a b c : ℕ,
a_1 : a = b,
a_2 : b = c
⊢ a = c
hello world
auto_quote_error2.lean:16:2: error: solve1 tactic failed, focused goal has not been solved
state:
a b c : ℕ,
a_1 : a = b,
a_2 : b = c
⊢ a = c
hello world
auto_quote_error2.lean:28:2: error: solve1 tactic failed, focused goal has not been solved
state:
a b c : ℕ,
a_1 : a = b,
a_2 : b = c
⊢ a = ?m_1
auto_quote_error2.lean:37:22: error: don't know how to synthesize placeholder
context:
a b c : ℕ,
h1 : a = b,
h2 : b = c
⊢ b = c
state:
a b c : ℕ,
h1 : a = b,
h2 : b = c
⊢ a = c
auto_quote_error2.lean:45:14: error: solve1 tactic failed, focused goal has not been solved
state:
b : ℕ,
h2 : b = 0
⊢ 0 = b
auto_quote_error2.lean:51:25: error: solve1 tactic failed, focused goal has not been solved
state:
3 goals
h' : ?m_2 = ?m_2
⊢ true

⊢ Sort ?

⊢ ?m_1