Created attachment 1309598 [details]
Test script to demonstrate the problem

Description of problem:

After an update of libstdc++ some of our in-house software no longer works. I can reproduce the problem with a simple test script, which shows that it is an incompatibility between root and the new libstdc++.

Version-Release number of selected component (if applicable):

libstdc++-6.4.1-1.fc25.x86_64
libstdc++-devel-6.4.1-1.fc25.x86_64
root-core-6.10.02-3.fc25.x86_64
root-cling-6.10.02-3.fc25.x86_64

How reproducible:

Always

Steps to Reproduce:
1. Using the attached script: root -q test.C++

Actual results:

Processing test.C++...
Info in <TUnixSystem::ACLiC>: creating shared library /tmp/./test_C.so
Warning in cling::IncrementalParser::CheckABICompatibility():
  Possible C++ standard library mismatch, compiled with __GLIBCXX__ '20161221'
  Extraction of runtime standard library version was: '20170727'
In file included from test_C_ACLiC_dict dictionary payload:10:
././test.C:1:10: fatal error: file '/usr/lib/gcc/x86_64-redhat-linux/6.4.1/../../../../include/c++/6.4.1/memory' modified since it was first processed
#include <memory>
         ^
Warning in <TInterpreter::TCling::RegisterModule>: Problems declaring payload for module test_C_ACLiC_dict.
input_line_11:2:3: error: use of undeclared identifier 'test'
 (test())
  ^

Expected results:
hello, world

Additional info:

There are two related, but separate issues. The warning of the C++ standard library mismatch and the error that the memory header was modified since it was first processed.

Recompiling the same version of root from the source rpm (using the new headers) and installing root-core again fixes the error and installing root-cling fixes the warning.

So it just needs a mock rebuild of root.