Installing 6.20.04 fails on Ubuntu 20.04

Trying to install Root 6.20.04 from source on
Kubuntu 20.04, a recent new installation.

Problem:
cmake fails to find correct Python (python 2.7 and 3.8 are installed, 3.8 is default)

Some more details
python -V Python 3.8.2 cmake --version
cmake version 3.16.3
$ cmake …/root-6.20.04/ 2>&1 |tee cmake.log
– The C compiler identification is GNU 9.3.0
– The CXX compiler identification is GNU 9.3.0
– Check for working C compiler: /usr/bin/cc
– Check for working C compiler: /usr/bin/cc – works
– Detecting C compiler ABI info
– Detecting C compiler ABI info - done
– Detecting C compile features
– Detecting C compile features - done
– Check for working CXX compiler: /usr/bin/c++
– Check for working CXX compiler: /usr/bin/c++ – works
– Detecting CXX compiler ABI info
– Detecting CXX compiler ABI info - done
– Detecting CXX compile features
– Detecting CXX compile features - done
– Found Git: /usr/bin/git (found version “2.25.1”)
– Looking for python
– Preferring Python version 3
CMake Error at /usr/share/cmake-3.16/Modules/FindPackageHandleStandardArgs.cmake:146 (message):
Could NOT find Python (missing: Interpreter) (found version “2.7”)
Call Stack (most recent call first):
/usr/share/cmake-3.16/Modules/FindPackageHandleStandardArgs.cmake:393 (_FPHSA_FAILURE_MESSAGE)
/usr/share/cmake-3.16/Modules/FindPython.cmake:347 (find_package_handle_standard_args)
cmake/modules/SearchRootCoreDeps.cmake:70 (find_package)

Any suggestions for how to proceed?
Thanks!

Btw, I also tried to install the precompiled root from homebrew, but it turns out that uses
an ancient gcc 5.5 and I really want a much newer compiler than that. Also it has so many optional
packages installed it ends up around 5 GB, including an entire Xorg installation…


Please read tips for efficient and successful posting and posting code

ROOT Version: 6.20.04
Platform: Kubuntu 20.04
Compiler: gcc 9.3


Try: sudo apt-get install python3-dev

Thanks, that did the trick. I also uninstalled python2.7 first, not going to use it anyway. -Haimo

@Axel So I just received shipment of a couple new laptops, and they were delivered with Ubuntu 20.04LTS, so I’ll be facing the same issues as the OP, presumably. When might we expect precompiled binaries for Ubuntu 20.04, though? I might wait to install if it’s fairly soon.

For the moment, you can “tar” the binaries that you compiled on one machine and “untar” them on another machines.
Just make sure that all required operating system shared libraries are also installed.

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.