Since D66174 I see failures of TestDataFormatterStdList in about 50% of runs on Fedora 30 x86_64 libstdc++.
I have found out that LLDB internally expects these RegularExpressions to be matched in their alphabetical order:
^std::(__cxx11::)?list<.+>(( )?&)?$ ^std::__[[:alnum:]]+::list<.+>(( )?&)?$
But since D66174 they are sometimes matched in reverse order. A simple ugly workaround is to just sort it for ite
ration. The overlapping matches one can see by another debug patch on top of it.
In fact it was only some luck it worked before as there is internally std::map<lldb::RegularExpressionSP, FormatterImpl> (FormattersContainer).