Philip Hyunsu Cho

@Sandy4321 It should suffice to replace `LogisticLoss()` with a squared error: ```python class SquaredError(): def __init__(self): pass def loss(self, y, y_pred): return 0.5 * ((y - y_pred) ** 2) #...

@Sandy4321 I don't think this example has all the regularization mechanism as XGBoost does, as the example is quite simplified. There are `min_samples_split`, `min_impurity`, and `max_depth`.

@szha Okay, let's keep this RFC open until MXNet 2.0 is released.

As the error message suggests, please use CMake to build.

@trivialfis This is a good time to port dmlc/xgboost#3982 to dmlc-core. I'd like to give it a try.

I agree that Python `logging` is nice. However, we need need logging in the C++ layer. Also, there is a large body of existing code using `LOG(INFO)`. That's why I'm...

Also, the standalone executables should be tested in the CI. Right now, they are not.

Are you cross-compiling to aarch64? The `check_cxx_compiler_flag()` macro attempts to compile with `-msse2`. If the host supports `-msse2` but the target does not, we'd have an issue.

Excellent resource: [C++ Concurrency in Action](https://www.amazon.com/dp/1617294691/ref=cm_sw_em_r_mt_dp_U_Jv2qDbG0A2SPK)

Potential deadlock in lock-free queue: ``` [----------] 2 tests from Lockfree [ RUN ] Lockfree.ConcurrentQueue ================== WARNING: ThreadSanitizer: lock-order-inversion (potential deadlock) (pid=12822) Cycle in lock order graph: M2609 (0x7b2400002f68) =>...