revert_fail.lean:5:2: error:invalid 'revert' tactic, hypothesis 'v' depends on 'n'
proof state:
A : Type,
n : nat,
v : vector A n
⊢ v = v
revert_fail.lean:6:0: error: don't know how to synthesize placeholder
A : Type,
n : nat,
v : vector A n
⊢ v = v
revert_fail.lean:6:0: error: failed to add declaration 'example' to environment, value has metavariables
remark: set 'formatter.hide_full_terms' to false to see the complete term
  λ (A : Type) (n : nat) (v : …),
    ?M_1
revert_fail.lean:11:2: error:invalid tactic, there are no goals to be solved
proof state:
no goals
revert_fail.lean:12:0: error: don't know how to synthesize placeholder
n : nat
⊢ n = n
revert_fail.lean:12:0: error: failed to add declaration 'example' to environment, value has metavariables
remark: set 'formatter.hide_full_terms' to false to see the complete term
  λ (n : nat),
    ?M_1
revert_fail.lean:16:2: error:invalid 'revert' tactic, unknown hypothesis 'm'
proof state:
n : nat
⊢ n = n
revert_fail.lean:17:0: error: don't know how to synthesize placeholder
n : nat
⊢ n = n
revert_fail.lean:17:0: error: failed to add declaration 'example' to environment, value has metavariables
remark: set 'formatter.hide_full_terms' to false to see the complete term
  λ (n : nat),
    ?M_1