GCC8: no dict for __pair_base

-- TEST COMMAND -- 

cd /mnt/build/wsincr/LABEL/ROOT-fedora29/SPEC/python3/roottest/root/io/prefetching

/usr/bin/timeout -s USR2 1770s make cleantest

-- BEGIN TEST OUTPUT --

--- root/io/prefetching/PrefetchReading.ref	2018-11-16 21:35:43.787000000 +0000

+++ root/io/prefetching/PrefetchReading.clog	2018-11-20 00:13:47.100000000 +0000

@@ -5,6 +5,9 @@

 The file has been opened, setting up the TTree

 Setup done. Starting to read the entries

 i = 0

+Warning in <TStreamerInfo::Build>: pair<int,float>: base class __pair_base<int,float> has no streamer or dictionary it will not be saved

+Warning in <TStreamerInfo::Build>: pair<unsigned int,unsigned int>: base class __pair_base<unsigned int,unsigned int> has no streamer or dictionary it will not be saved

+Warning in <TStreamerInfo::Build>: pair<ElementLink_p2<unsigned int>,vector<ElementLink_p2<unsigned int> > >: base class __pair_base<ElementLink_p2<unsigned int>,vector<ElementLink_p2<unsigned int> > > has no streamer or dictionary it will not be saved

 i = 1000

 i = 2000

 i = 3000

-- END TEST OUTPUT --

-- BEGIN TEST ERROR --

--- Using ROOT from /mnt/build/wsincr/LABEL/ROOT-fedora29/SPEC/python3/build

make: *** [Makefile:96: PrefetchReading] Error 1