The linking with -lpython3 is right there in between libTree and libGraf …
However, there is on the contrary no path pointing to it …
Yes, you can use v5.34 with p3 (that’s why all those PyUnicode_XYZ symbols show up from PyROOT …), with some minor limitations (I forget the details): there were only one or two p3 users at the time, and I made things work for them, but not all of roottest.
However, you’d have to use a p3 that was concurrent in time with v5.34, which would be p3.2 or so. at best.