ROOT module not found: Python3

I believe so because I added

source /usr/local/bin/

to my ~/.bashrc

You showed /home/matthewlee4123/Products/root
So, it should be /home/matthewlee4123/Products/root/bin/

BTW. You’d better get completely rid of the ROOT distribution which you have in “/usr/local”.

@etejedor could you help out, please?

If you are building with experimental PyROOT you should not see anymore, now there are other libraries. Can you check if you see or ?

A priori the messages that CMake prints look ok, it found interpreter and development packages for Python3, so it should be building PyROOT with that one. It should not matter because it already found the python you wanted, but -DPYTHON=/usr... should be -DPYTHON_LIBRARIES=....

Also mentioning @maxgalli and @oshadura so they are aware.

There is a full list of all built libraries in one of the previous posts (and running “make” again doesn’t complain about anything, as shown in another previous post).

Can it be that the building of ROOT went amok because there’s another ROOT distribution in “/usr/local”?

Can you try the following?

cmake …/root-6.20.04 -Dpyroot_experimental=ON -DPYTHON_EXECUTABLE=/usr/bin/python3



then try once again to import ROOT from the python3 prompt.

(Just in case, either do it in a new build directory or remove CMakeCache.txt first)

Hello @maxgalli - I tried building with those flags and now I am receiving the error:

free(): invalid pointer
Aborted (core dumped)

What are you executing that lead to those errors? Are you sure there is no mixing of ROOT releases/builds in the environment?

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