failures are not very legible

For example

XGBoostClassifier: Test Failed at /home/expandingman/.julia/dev/MLJXGBoostInterface/test/runtests.jl:235
  Expression: isempty(failures)
   Evaluated: isempty(NamedTuple{(:name, :package_name, :test, :exception), NTuple{4, Any}}[NamedTuple{(:name, :package_name, :test, :exception), NTuple{4, Any}}(("XGBoostClassifier", "XGBoost", "fitted_machine", ErrorException("Call to XGBoost C function XGBoosterUpdateOneIter failed: [18:48:00] /workspace/srcdir/xgboost/src/objective/regression_obj.cu:36: Check failed: info.labels.Size() == preds.Size() (200 vs. 400) : Invalid shape of labels.\nStack trace:\n  [bt] (0) /home/expandingman/.julia/artifacts/501324fbf7eec8ade7ee93955843c5cbdbd43fdc/lib/libxgboost.so(+0x32baa7) [0x7f9f5cfa9aa7]\n  [bt] (1) /home/expandingman/.julia/artifacts/501324fbf7eec8ade7ee93955843c5cbdbd43fdc/lib/libxgboost.so(+0x32bd53) [0x7f9f5cfa9d53]\n  [bt] (2) /home/expandingman/.julia/artifacts/501324fbf7eec8ade7ee93955843c5cbdbd43fdc/lib/libxgboost.so(xgboost::obj::RegLossObj<xgboost::obj::LogisticClassification>::GetGradient(xgboost::HostDeviceVector<float> const&, xgboost::MetaInfo const&, int, xgboost::HostDeviceVector<xgboost::detail::GradientPairInternal<float> >*)+0x29) [0x7f9f5cfbcf49]\n  [bt] (3) /home/expandingman/.julia/artifacts/501324fbf7eec8ade7ee93955843c5cbdbd43fdc/lib/libxgboost.so(xgboost::LearnerImpl::UpdateOneIter(int, std::shared_ptr<xgboost::DMatrix>)+0x295) [0x7f9f5cef1f15]\n  [bt] (4) /home/expandingman/.julia/artifacts/501324fbf7eec8ade7ee93955843c5cbdbd43fdc/lib/libxgboost.so(XGBoosterUpdateOneIter+0x42) [0x7f9f5cd99ba2]\n  [bt] (5) [0x7fa0047cb7a8]\n  [bt] (6) [0x7fa0047cc32b]\n  [bt] (7) [0x7fa0047cd11b]\n  [bt] (8) [0x7fa0047cd1ac]\n\n")))])

It doesn't help that the Test stdlib doesn't have very good printing which I believe is producing this output, however the situation is exacerbated with these integration tests because it's harder to track down the exact test that failed.

I suggest that some try catching to print errors more legibly may be appropriate.

Start in test/runtests.jl around line 235 and inspect how the Julia Test stdlib prints the integration failure. Compare the current output with the requested legibility, including identifying the exact failing test and presenting the exception more clearly; done means failures are concise and actionable.