FTBFS: Can't generate root dictionaries on ifarm

[DraTeots]

The issue is straight forward to reproduce. On ifarm:

Environment:

source /cvmfs/eic.opensciencegrid.org/packages/setup-env.sh
spack load --first eic os=centos7
spack load --first gcc os=centos7

Example package:

mkdir dirc && cd dirc
git clone https://github.com/rdom/prttools
git clone https://github.com/rdom/eicdirc
mkdir build && cd build
cmake -DCMAKE_CXX_STANDARD=17 -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON ../eicdirc

Resulting error:

../rootcling -v2 -f G__Prt.cxx -s /home/romanov/dirc/build/libPrt.so -rml libPrt.so -rmf /home/romanov/dirc/build/libPrt.rootmap -DG4UI_USE_TCSH -DG4INTY_USE_QT -DG4UI_USE_QT -DG4VIS_USE_OPENGLQT -DG4VIS_USE_OPENGL -I/cvmfs/eic.opensciencegrid.org/packages/clhep/2.4.1.3/linux-centos7-x86_64-gcc-9.3.0-vpphhq4z55o6paocmxi2tgsowvog3q73/lib/CLHEP-2.4.1.3/../../include -I/cvmfs/eic.opensciencegrid.org/packages/geant4/10.6.2/linux-centos7-x86_64-gcc-9.3.0-bdlgoee3hwsaszkcxbgapbmx2xjemwmc/include/Geant4 -I/cvmfs/eic.opensciencegrid.org/packages/root/6.20.04/linux-centos7-x86_64-gcc-9.3.0-qiipdiw4t4m3mgmy6mjiixfmv2poh43w/include -I/home/romanov/dirc/eicdirc/src -I/home/romanov/dirc/eicdirc -std=c++17 PrtHit.h PrtEvent.h PrtLutNode.h PrtAmbiguityInfo.h PrtPhotonInfo.h PrtTrackInfo.h /home/romanov/dirc/eicdirc/src/PrtLinkDef.h


In file included from input_line_11:18:
In file included from /home/romanov/dirc/eicdirc/src/PrtHit.h:13:

In file included from /cvmfs/eic.opensciencegrid.org/packages/root/6.20.04/linux-centos7-x86_64-gcc-9.3.0-qiipdiw4t4m3mgmy6mjiixfmv2poh43w/include/TVector3.h:16:

...
In file included from /cvmfs/eic.opensciencegrid.org/packages/root/6.20.04/linux-centos7-x86_64-gcc-9.3.0-qiipdiw4t4m3mgmy6mjiixfmv2poh43w/include/TString.h:28:

/cvmfs/eic.opensciencegrid.org/packages/root/6.20.04/linux-centos7-x86_64-gcc-9.3.0-qiipdiw4t4m3mgmy6mjiixfmv2poh43w/include/ROOT/RStringView.hxx:19:10: fatal error: 'string_view' file not found
#include <string_view>

So the error is with rootcling and my guess, that it happens because old libstdc++ is used by rootcling:

/sbin/ldconfig -p | grep stdc++
        libstdc++.so.6 (libc6,x86-64) => /lib64/libstdc++.so.6
        libstdc++.so.6 (libc6) => /lib/libstdc++.so.6

This QA kind of agrees with me. But it is not 100% clear.

Why it is here? - first, because everything builds on my ubuntu 18.04 and 20.04 and it kind of a problem of spack+ifarm environment, so all other users compiling somehting with root IO will be in the same trap. Finally I hope for Wouter's help as I feel helpless in the face of ifarm and cvmfs installation at this point (tried building it for 3 weeks).

Why -DCMAKE_CXX_STANDARD=17 and root ~gminimal? - When first I tried to build things on my machine, I stumbled at string_view issue. But that was another issue, standard root header problem which is solved by -std=c++17 on compiler level. Then I experienced TSpectre problem and came to ~gminimal. But when it still didn't work on ifarm I figured out that the problem is different and it is in cling. My hope was on updated environment with gcc provided by spack, but it didn't help.

[DraTeots]

CMake output

 cmake -DCMAKE_CXX_STANDARD=17 ../eicdirc
-- The C compiler identification is GNU 9.3.0
-- The CXX compiler identification is GNU 9.3.0
-- Check for working C compiler: /cvmfs/eic.opensciencegrid.org/packages/gcc/9.3.0/linux-centos7-x86_64-gcc-4.8.5-t6vopxdfdkglw5wuh4zqsehr5thkkyub/bin/gcc
-- Check for working C compiler: /cvmfs/eic.opensciencegrid.org/packages/gcc/9.3.0/linux-centos7-x86_64-gcc-4.8.5-t6vopxdfdkglw5wuh4zqsehr5thkkyub/bin/gcc - 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: /cvmfs/eic.opensciencegrid.org/packages/gcc/9.3.0/linux-centos7-x86_64-gcc-4.8.5-t6vopxdfdkglw5wuh4zqsehr5thkkyub/bin/g++
-- Check for working CXX compiler: /cvmfs/eic.opensciencegrid.org/packages/gcc/9.3.0/linux-centos7-x86_64-gcc-4.8.5-t6vopxdfdkglw5wuh4zqsehr5thkkyub/bin/g++ - works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found EXPAT: /cvmfs/eic.opensciencegrid.org/packages/expat/2.2.9/linux-centos7-x86_64-gcc-9.3.0-w6wxu25wm7i4e2hvtioqjuzrdgi27i4b/lib/libexpat.so (found suitable version "2.2.9", minimum required is "2.2.9")
-- Found ZLIB: /cvmfs/eic.opensciencegrid.org/packages/zlib/1.2.11/linux-centos7-x86_64-gcc-9.3.0-o5eyrr46zecie66pglu4lamuqvhpcrkl/lib/libz.so (found suitable version "1.2.11", minimum required is "1.2.11")
-- Found XercesC: /cvmfs/eic.opensciencegrid.org/packages/xerces-c/3.2.2/linux-centos7-x86_64-gcc-9.3.0-ouw3pyhy3crsgrhsyxe2hdfyvyyplmpk/lib/libxerces-c.so (found suitable version "3.2.2", minimum required is "3.2.2")
-- Found OpenGL: /usr/lib64/libOpenGL.so
-- Configuring done
-- Generating done
-- Build files have been written to: /home/romanov/dirc/build