Explain what you would like to see improved and how.

Hi,

In many analyses we need to match two TChains (e.g. reco and truth) using the TTreeIndex or BuildIndex() functionality. It is very convenient for us to work with TChains, but this often results in these errors:

Error in <TChainIndex::TChainIndex>: The indices in files of this chain aren't sorted.
Error in <TTreePlayer::BuildIndex>: Creating a TChainIndex unsuccessful - switching to TTreeIndex

After discussing also with @vepadulano, we believe these are not real error sbut more like warnings and the code produces correct results. We also have no way how to modify the inputs to get rid of the errors. The error is often printed multiple times, flooding the terminal output. It would be nice to have an option to suppress these errors

ROOT version

all versions that support BuldIndex() functionality

Installation method

any

Operating system

any

Additional context

No response