无法同时满足tableHeaderView的约束

Question

这是代码：

- (void)viewDidLoad {
    [super viewDidLoad];
    .....
    self.tableView.tableHeaderView = [self headerView];
//
/*  If I addSubView instead of set to tableHeaderView, the constraint is OK. */
/*  [self.view addSubview:[self headerView]];  */
//
}
- (UIView *)headerView {
    UIView *headerView = [UIView new];
    headerView.frame = CGRectMake(0, 0, 375, 270);
    UIView *v1 = [UIView new];
    [headerView addSubview:v1];
    v1.backgroundColor = [UIColor redColor];
    [v1 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(headerView);
        make.bottom.equalTo(headerView);
        make.width.equalTo(@100);
        make.height.equalTo(@50);
    }];
    UIView *v2 = [UIView new];
    v2.backgroundColor = [UIColor blueColor];
    [headerView addSubview:v2];
    [v2 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(v1.mas_right);
        make.right.equalTo(headerView);
        make.height.bottom.equalTo(v1);
    }];
    return headerView;
}

当我运行此代码时，模拟器显示正确的UI，但控制台显示：

Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. 
    Try this: 
        (1) look at each constraint and try to figure out which you don't expect; 
        (2) find the code that added the unwanted constraint or constraints and fix it. 
(
    "<MASLayoutConstraint:0x7fc79143bf40 UIView:0x7fc7913992d0.left == UIView:0x7fc79136fa60.left>",
    "<MASLayoutConstraint:0x7fc79143cc00 UIView:0x7fc7913992d0.width == 100>",
    "<MASLayoutConstraint:0x7fc79143b8e0 UIView:0x7fc79140bd30.left == UIView:0x7fc7913992d0.right>",
    "<MASLayoutConstraint:0x7fc79143ea70 UIView:0x7fc79140bd30.right == UIView:0x7fc79136fa60.right>",
    "<NSLayoutConstraint:0x7fc790ffb950 UIView:0x7fc79136fa60.width == 0>"
)
Will attempt to recover by breaking constraint 
<MASLayoutConstraint:0x7fc79143cc00 UIView:0x7fc7913992d0.width == 100>

代码有问题吗？或者tableHeaderView和autoLayout ??

有什么问题