How can I suppress error messages from Cling's compilation of a TFormula?

ROOT
1

Doing something like:

TFormula ff( "", "max(0,1.)" )

results in many lines of error messages.
I use TFormula in a context where I catch such errors through TFormula.IsValid. So they are a nuisance. The usual ROOT trick of setting gErrorIgnoreLevel to a high-enough level does not work.

How can I suppress them?

2

The error printed within TFormula can be suppressed by increasing the gErrorIgnoreLevel. The other compilation errors are coming from Cling.
@Axel should know if it is possible to suppress them

Lorenzo