TMVA installation error i have tried a lot of times with root version 6.18-04

TMVA
1

Compiling src/GeneticAlgorithm.cxx … Compiling src/TSpline2.cxx … Compiling src/ResultsMulticlass.cxx … Compiling src/PDF.cxx … In file included from ./TMVA/GeneticAlgorithm.h:44,
from src/GeneticAlgorithm.cxx:38:
./TMVA/GeneticPopulation.h:40:10: fatal error: Riosfwd.h: No such file or directory
40 | #include “Riosfwd.h”
| ^~~~~~~~~~~
compilation terminated.
make: *** [Makefile:97: obj/GeneticAlgorithm.o] Error 1
make: *** Waiting for unfinished jobs…
In file included from ./TMVA/GeneticAlgorithm.h:44,
from src/ResultsMulticlass.cxx:37:
./TMVA/GeneticPopulation.h:40:10: fatal error: Riosfwd.h: No such file or directory
40 | #include “Riosfwd.h”
| ^~~~~~~~~~~
compilation terminated.
make: *** [Makefile:97: obj/ResultsMulticlass.o] Error 1

2

It seems to me that you mixed source code coming from different ROOT versions (i.e. your “TMVA” is not the one included in your ROOT 6.18/04).