Python and ROOT when installing in WSL / Ubuntu

ROOT
2

It’s not only in Python. Even running fillrandom.C (from tutorials/hist) alone in root 6 (Ubuntu 18.04, WSL), it hangs, with messages like:

cling::DynamicLibraryManager::loadLibrary(): libgsl.so.23: cannot open shared object file: No such file or directory
Error in <TInterpreter::TCling::AutoLoad>: failure loading library libMathMore.so for ROOT::Math::GSLIntegrator
cling::DynamicLibraryManager::loadLibrary(): libgsl.so.23: cannot open shared object file: No such file or directory
Warning in <ROOT::Math::IntegratorOneDim::CreateIntegrator>: Error loading one dimensional GSL integrator - use Gauss integrator

Here is a reduced example based on fillrandom:

void fillran1() {
   TCanvas *c1 = new TCanvas("c1","The FillRandom example",200,10,700,900);

   TFormula *form1 = new TFormula("form1","abs(sin(x)/x)");
   TF1 *sqroot = new TF1("sqroot","x*gaus(0) + [3]*form1",0,10);
   sqroot->SetParameters(10,4,1,20);
/*
   // works with these two instead:
   TF1 *sqroot = new TF1("sqroot","gaus(0)",0,10);
   sqroot->SetParameters(10,4,1);
*/
   sqroot->Draw();

   TH1F *h1f = new TH1F("h1f","Test random numbers",200,0,10);
   h1f->FillRandom("sqroot",1000);  // fails here
   h1f->Draw();
}

It looks like the problem is when sqroot includes “x”, but even adding a number (“gaus(0) + 3”), breaks it.

However, it works fine on root 5.34/38 on Windows.