X11 problem

You seem to have another version of ROOT in “/usr/local/root”.

How is it possible that “root-config” has been found without calling “source /…/bin/thisroot.sh” first?
Try:
which root-config
type root-config
echo $PATH
echo $LD_LIBRARY_PATH

Can it be that you put “/usr/local/root/lib” in the ld.so cache? Try:
/sbin/ldconfig -v|grep root

Try also:
ls -aliR /usr/local/root/lib

physics@physics-VirtualBox:~$ which root-config
/home/physics/root-v5-34/bin/root-config
physics@physics-VirtualBox:~$ type root-config
root-config is /home/physics/root-v5-34/bin/root-config
physics@physics-VirtualBox:~$ echo $PATH
/home/physics/root-v5-34/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
physics@physics-VirtualBox:~$ echo $LD_LIBRARY_PATH
/home/physics/root-v5-34/lib

physics@physics-VirtualBox:~$ /sbin/ldconfig -v|grep root
/sbin/ldconfig.real: Can’t stat /lib/i686-linux-gnu: No such file or directory
/sbin/ldconfig.real: Can’t stat /usr/lib/i686-linux-gnu: No such file or directory
/sbin/ldconfig.real: Path /lib/i386-linux-gnu' given more than once /sbin/ldconfig.real: Path/usr/lib/i386-linux-gnu’ given more than once
/sbin/ldconfig.real: Can’t create temporary cache file /etc/ld.so.cache~: Permission denied
physics@physics-VirtualBox:~$ ls -aliR /usr/local/root/lib
/usr/local/root/lib:
total 136000
791161 drwxrwxr-x 3 physics physics 12288 Jun 25 14:59 .
658433 drwxrwxr-x 39 physics physics 4096 Jun 25 14:59 …
792750 -rw-rw-r-- 1 physics physics 1207056 Jun 25 14:39 libAfterImage.a
792825 -rw-rw-r-- 1 physics physics 117 Jun 25 14:58 libASImageGui.rootmap
792751 -rwxrwxr-x 1 physics physics 142696 Jun 25 14:39 libASImageGui.so
792824 -rw-rw-r-- 1 physics physics 252 Jun 25 14:58 libASImage.rootmap
792749 -rwxrwxr-x 1 physics physics 1237890 Jun 25 14:39 libASImage.so
792828 -rw-rw-r-- 1 physics physics 70 Jun 25 14:58 libCintex.rootmap
792754 -rwxrwxr-x 1 physics physics 224684 Jun 25 14:44 libCintex.so
792180 -rwxrwxr-x 1 physics physics 2719768 Jun 25 14:07 libCint.so
792775 -rw-rw-r-- 1 physics physics 280 Jun 25 14:58 libcomplexDict.rootmap
792695 -rwxrwxr-x 1 physics physics 27529 Jun 25 14:13 libcomplexDict.so
792763 -rw-rw-r-- 1 physics physics 12542 Jun 25 14:58 libCore.rootmap
792533 -rwxrwxr-x 1 physics physics 8817383 Jun 25 14:10 libCore.so
792767 -rw-rw-r-- 1 physics physics 324 Jun 25 14:58 libdequeDict.rootmap
792687 -rwxrwxr-x 1 physics physics 144950 Jun 25 14:13 libdequeDict.so
792796 -rw-rw-r-- 1 physics physics 927 Jun 25 14:58 libEG.rootmap
792721 -rwxrwxr-x 1 physics physics 467201 Jun 25 14:27 libEG.so
795656 -rw-rw-r-- 1 physics physics 53421 Jun 25 14:58 libEve.rootmap
795657 -rwxrwxr-x 1 physics physics 5920409 Jun 25 14:38 libEve.so
795658 -rw-rw-r-- 1 physics physics 220 Jun 25 14:58 libFFTW.rootmap
795659 -rwxrwxr-x 1 physics physics 1624460 Jun 25 14:39 libFFTW.so
792813 -rw-rw-r-- 1 physics physics 512 Jun 25 14:58 libFitPanel.rootmap
792738 -rwxrwxr-x 1 physics physics 438697 Jun 25 14:31 libFitPanel.so
795660 -rw-rw-r-- 1 physics physics 103 Jun 25 14:58 libFITSIO.rootmap
795661 -rwxrwxr-x 1 physics physics 1531740 Jun 25 14:39 libFITSIO.so
792806 -rw-rw-r-- 1 physics physics 486 Jun 25 14:58 libFoam.rootmap
792731 -rwxrwxr-x 1 physics physics 288608 Jun 25 14:29 libFoam.so
792800 -rw-rw-r-- 1 physics physics 188 Jun 25 14:58 libFumili.rootmap
792725 -rwxrwxr-x 1 physics physics 166185 Jun 25 14:29 libFumili.so
795664 -rw-rw-r-- 1 physics physics 297 Jun 25 14:58 libGdml.rootmap
795665 -rwxrwxr-x 1 physics physics 507737 Jun 25 14:53 libGdml.so
792790 -rw-rw-r-- 1 physics physics 4125 Jun 25 14:58 libGed.rootmap
792715 -rwxrwxr-x 1 physics physics 1794579 Jun 25 14:26 libGed.so
792832 -rw-rw-r-- 1 physics physics 203 Jun 25 14:58 libGenetic.rootmap
792761 -rwxrwxr-x 1 physics physics 181546 Jun 25 14:58 libGenetic.so
792826 -rw-rw-r-- 1 physics physics 8910 Jun 25 14:58 libGenVector.rootmap
792752 -rwxrwxr-x 1 physics physics 2903756 Jun 25 14:41 libGenVector.so
792810 -rw-rw-r-- 1 physics physics 4608 Jun 25 14:58 libGeomBuilder.rootmap
792735 -rwxrwxr-x 1 physics physics 1580769 Jun 25 14:31 libGeomBuilder.so
792798 -rw-rw-r-- 1 physics physics 576 Jun 25 14:58 libGeomPainter.rootmap
792723 -rwxrwxr-x 1 physics physics 390401 Jun 25 14:28 libGeomPainter.so
792797 -rw-rw-r-- 1 physics physics 8277 Jun 25 14:58 libGeom.rootmap
792722 -rwxrwxr-x 1 physics physics 4337952 Jun 25 14:28 libGeom.so
792784 -rw-rw-r-- 1 physics physics 1564 Jun 25 14:58 libGpad.rootmap
792709 -rwxrwxr-x 1 physics physics 1050803 Jun 25 14:22 libGpad.so
795662 -rw-rw-r-- 1 physics physics 1067 Jun 25 14:58 libGQt.rootmap
795663 -rwxrwxr-x 1 physics physics 826218 Jun 25 14:40 libGQt.so
792785 -rw-rw-r-- 1 physics physics 3360 Jun 25 14:58 libGraf3d.rootmap
792710 -rwxrwxr-x 1 physics physics 1257397 Jun 25 14:22 libGraf3d.so
792783 -rw-rw-r-- 1 physics physics 4056 Jun 25 14:58 libGraf.rootmap
792708 -rwxrwxr-x 1 physics physics 2198527 Jun 25 14:21 libGraf.so
792804 -rw-rw-r-- 1 physics physics 651 Jun 25 14:58 libGuiBld.rootmap
792729 -rwxrwxr-x 1 physics physics 654455 Jun 25 14:29 libGuiBld.so
792818 -rw-rw-r-- 1 physics physics 178 Jun 25 14:58 libGuiHtml.rootmap
792743 -rwxrwxr-x 1 physics physics 449648 Jun 25 14:33 libGuiHtml.so
792786 -rw-rw-r-- 1 physics physics 20503 Jun 25 14:58 libGui.rootmap
792711 -rwxrwxr-x 1 physics physics 8308238 Jun 25 14:24 libGui.so
795668 -rw-rw-r-- 1 physics physics 665 Jun 25 14:58 libGviz3d.rootmap
795669 -rwxrwxr-x 1 physics physics 347317 Jun 25 14:38 libGviz3d.so
795666 -rw-rw-r-- 1 physics physics 231 Jun 25 14:58 libGviz.rootmap
795667 -rwxrwxr-x 1 physics physics 136757 Jun 25 14:39 libGviz.so
792820 -rw-rw-r-- 1 physics physics 55 Jun 25 14:58 libGX11.rootmap
792745 -rwxrwxr-x 1 physics physics 280162 Jun 25 14:33 libGX11.so
792821 -rw-rw-r-- 1 physics physics 80 Jun 25 14:58 libGX11TTF.rootmap
792746 -rwxrwxr-x 1 physics physics 115738 Jun 25 14:34 libGX11TTF.so
792829 -rw-rw-r-- 1 physics physics 576 Jun 25 14:58 libHbook.rootmap
792757 -rwxrwxr-x 1 physics physics 205051 Jun 25 14:54 libHbook.so
795670 -rw-rw-r-- 1 physics physics 5709 Jun 25 14:58 libHistFactory.rootmap
795671 -rwxrwxr-x 1 physics physics 3202289 Jun 25 14:53 libHistFactory.so
792788 -rw-rw-r-- 1 physics physics 615 Jun 25 14:58 libHistPainter.rootmap
792713 -rwxrwxr-x 1 physics physics 690863 Jun 25 14:25 libHistPainter.so
792781 -rw-rw-r-- 1 physics physics 12533 Jun 25 14:58 libHist.rootmap
792706 -rwxrwxr-x 1 physics physics 5875155 Jun 25 14:20 libHist.so
792795 -rw-rw-r-- 1 physics physics 1501 Jun 25 14:58 libHtml.rootmap
792720 -rwxrwxr-x 1 physics physics 981475 Jun 25 14:27 libHtml.so
795672 -rw-rw-r-- 1 physics physics 84 Jun 25 14:58 libKrb5Auth.rootmap
795673 -rwxrwxr-x 1 physics physics 86581 Jun 25 14:54 libKrb5Auth.so
792766 -rw-rw-r-- 1 physics physics 371 Jun 25 14:58 liblistDict.rootmap
792686 -rwxrwxr-x 1 physics physics 84380 Jun 25 14:13 liblistDict.so
792470 -rw-rw-r-- 1 physics physics 257192 Jun 25 14:09 liblzma.a
792769 -rw-rw-r-- 1 physics physics 689 Jun 25 14:58 libmap2Dict.rootmap
792689 -rwxrwxr-x 1 physics physics 160209 Jun 25 14:13 libmap2Dict.so
792768 -rw-rw-r-- 1 physics physics 572 Jun 25 14:58 libmapDict.rootmap
792688 -rwxrwxr-x 1 physics physics 146422 Jun 25 14:13 libmapDict.so
792778 -rw-rw-r-- 1 physics physics 6358 Jun 25 14:58 libMathCore.rootmap
792698 -rwxrwxr-x 1 physics physics 2783298 Jun 25 14:16 libMathCore.so
792827 -rw-rw-r-- 1 physics physics 4409 Jun 25 14:58 libMathMore.rootmap
792753 -rwxrwxr-x 1 physics physics 2491057 Jun 25 14:42 libMathMore.so
793106 -rw-rw-r-- 1 physics physics 418378 Jun 25 14:21 libmathtext.a
792780 -rw-rw-r-- 1 physics physics 7560 Jun 25 14:58 libMatrix.rootmap
792700 -rwxrwxr-x 1 physics physics 2751650 Jun 25 14:17 libMatrix.so
792823 -rw-rw-r-- 1 physics physics 224 Jun 25 14:58 libMemStat.rootmap
792748 -rwxrwxr-x 1 physics physics 168350 Jun 25 14:38 libMemStat.so
792756 -rwxrwxr-x 1 physics physics 183375 Jun 25 14:54 libminicern.so
795674 -rw-rw-r-- 1 physics physics 3578 Jun 25 14:58 libMinuit2.rootmap
795675 -rwxrwxr-x 1 physics physics 1552553 Jun 25 14:43 libMinuit2.so
792787 -rw-rw-r-- 1 physics physics 535 Jun 25 14:58 libMinuit.rootmap
792712 -rwxrwxr-x 1 physics physics 612701 Jun 25 14:24 libMinuit.so
792801 -rw-rw-r-- 1 physics physics 572 Jun 25 14:58 libMLP.rootmap
792726 -rwxrwxr-x 1 physics physics 408101 Jun 25 14:29 libMLP.so
792772 -rw-rw-r-- 1 physics physics 580 Jun 25 14:58 libmultimap2Dict.rootmap
792692 -rwxrwxr-x 1 physics physics 125035 Jun 25 14:13 libmultimap2Dict.so
792771 -rw-rw-r-- 1 physics physics 513 Jun 25 14:58 libmultimapDict.rootmap
792691 -rwxrwxr-x 1 physics physics 118721 Jun 25 14:13 libmultimapDict.so
792773 -rw-rw-r-- 1 physics physics 399 Jun 25 14:58 libmultisetDict.rootmap
792693 -rwxrwxr-x 1 physics physics 91633 Jun 25 14:13 libmultisetDict.so
792779 -rw-rw-r-- 1 physics physics 2844 Jun 25 14:58 libNet.rootmap
792699 -rwxrwxr-x 1 physics physics 1637127 Jun 25 14:17 libNet.so
792705 -rwxrwxr-x 1 physics physics 22748 Jun 25 14:17 libNew.so
792293 -rw-rw-r-- 1 physics physics 184440 Jun 21 14:59 libpcre.a
792792 -rw-rw-r-- 1 physics physics 860 Jun 25 14:58 libPhysics.rootmap
792717 -rwxrwxr-x 1 physics physics 723762 Jun 25 14:27 libPhysics.so
792793 -rw-rw-r-- 1 physics physics 288 Jun 25 14:58 libPostscript.rootmap
792718 -rwxrwxr-x 1 physics physics 452399 Jun 25 14:27 libPostscript.so
792830 -rw-rw-r-- 1 physics physics 1500 Jun 25 14:58 libProofBench.rootmap
792759 -rwxrwxr-x 1 physics physics 503263 Jun 25 14:54 libProofBench.so
792816 -rw-rw-r-- 1 physics physics 2712 Jun 25 14:58 libProofDraw.rootmap
792741 -rwxrwxr-x 1 physics physics 416806 Jun 25 14:33 libProofDraw.so
792815 -rw-rw-r-- 1 physics physics 3744 Jun 25 14:58 libProofPlayer.rootmap
792740 -rwxrwxr-x 1 physics physics 1070324 Jun 25 14:33 libProofPlayer.so
792814 -rw-rw-r-- 1 physics physics 4380 Jun 25 14:58 libProof.rootmap
792739 -rwxrwxr-x 1 physics physics 2444007 Jun 25 14:32 libProof.so
795676 -rw-rw-r-- 1 physics physics 456 Jun 25 14:58 libPyROOT.rootmap
795677 -rwxrwxr-x 1 physics physics 810264 Jun 25 14:40 libPyROOT.so
795678 -rw-rw-r-- 1 physics physics 539 Jun 25 14:58 libQtGSI.rootmap
795679 -rwxrwxr-x 1 physics physics 342720 Jun 25 14:40 libQtGSI.so
795680 -rw-rw-r-- 1 physics physics 77 Jun 25 14:58 libQtRoot.rootmap
795681 -rwxrwxr-x 1 physics physics 76244 Jun 25 14:40 libQtRoot.so
792802 -rw-rw-r-- 1 physics physics 966 Jun 25 14:58 libQuadp.rootmap
792727 -rwxrwxr-x 1 physics physics 587146 Jun 25 14:29 libQuadp.so
792819 -rw-rw-r-- 1 physics physics 1236 Jun 25 14:58 libRecorder.rootmap
792744 -rwxrwxr-x 1 physics physics 407627 Jun 25 14:33 libRecorder.so
792764 -rw-rw-r-- 1 physics physics 2963 Jun 25 14:58 libReflexDict.rootmap
792651 -rwxrwxr-x 1 physics physics 944681 Jun 25 14:11 libReflexDict.so
792646 -rwxrwxr-x 1 physics physics 725595 Jun 25 14:11 libReflex.so
795682 -rw-rw-r-- 1 physics physics 17024 Jun 25 14:58 libRGL.rootmap
795683 -rwxrwxr-x 1 physics physics 4327257 Jun 25 14:36 libRGL.so
792794 -rw-rw-r-- 1 physics physics 110 Jun 25 14:58 libRint.rootmap
792719 -rwxrwxr-x 1 physics physics 239764 Jun 25 14:27 libRint.so
792777 -rw-rw-r-- 1 physics physics 2288 Jun 25 14:58 libRIO.rootmap
792697 -rwxrwxr-x 1 physics physics 3954971 Jun 25 14:15 libRIO.so
795684 -rw-rw-r-- 1 physics physics 224 Jun 25 14:58 libRLDAP.rootmap
795685 -rwxrwxr-x 1 physics physics 145471 Jun 25 14:54 libRLDAP.so
795686 -rw-rw-r-- 1 physics physics 308 Jun 25 14:58 libRMySQL.rootmap
795687 -rwxrwxr-x 1 physics physics 173473 Jun 25 14:38 libRMySQL.so
795690 -rw-rw-r-- 1 physics physics 37767 Jun 25 14:58 libRooFitCore.rootmap
795691 -rwxrwxr-x 1 physics physics 10317791 Jun 25 14:49 libRooFitCore.so
795688 -rw-rw-r-- 1 physics physics 15022 Jun 25 14:58 libRooFit.rootmap
795689 -rwxrwxr-x 1 physics physics 5048142 Jun 25 14:51 libRooFit.so
795692 -rw-rw-r-- 1 physics physics 14095 Jun 25 14:58 libRooStats.rootmap
795693 -rwxrwxr-x 1 physics physics 2852865 Jun 25 14:52 libRooStats.so
792803 -rw-rw-r-- 1 physics physics 316 Jun 25 14:58 libRootAuth.rootmap
792728 -rwxrwxr-x 1 physics physics 407036 Jun 25 14:29 libRootAuth.so
792817 -rw-rw-r-- 1 physics physics 2465 Jun 25 14:58 libSessionViewer.rootmap
792742 -rwxrwxr-x 1 physics physics 939471 Jun 25 14:33 libSessionViewer.so
792770 -rw-rw-r-- 1 physics physics 364 Jun 25 14:58 libsetDict.rootmap
792690 -rwxrwxr-x 1 physics physics 91426 Jun 25 14:13 libsetDict.so
792808 -rw-rw-r-- 1 physics physics 10924 Jun 25 14:58 libSmatrix.rootmap
792733 -rwxrwxr-x 1 physics physics 3683795 Jun 25 14:30 libSmatrix.so
792812 -rw-rw-r-- 1 physics physics 88 Jun 25 14:58 libSpectrumPainter.rootmap
792737 -rwxrwxr-x 1 physics physics 291209 Jun 25 14:31 libSpectrumPainter.so
792811 -rw-rw-r-- 1 physics physics 581 Jun 25 14:58 libSpectrum.rootmap
792736 -rwxrwxr-x 1 physics physics 651702 Jun 25 14:31 libSpectrum.so
792807 -rw-rw-r-- 1 physics physics 147 Jun 25 14:58 libSPlot.rootmap
792732 -rwxrwxr-x 1 physics physics 115429 Jun 25 14:29 libSPlot.so
792809 -rw-rw-r-- 1 physics physics 836 Jun 25 14:58 libSQLIO.rootmap
792734 -rwxrwxr-x 1 physics physics 778411 Jun 25 14:30 libSQLIO.so
792758 -rwxrwxr-x 1 physics physics 157118 Jun 25 14:54 libSrvAuth.so
795694 -rw-rw-r-- 1 physics physics 4140 Jun 25 14:58 libTable.rootmap
795695 -rwxrwxr-x 1 physics physics 1546185 Jun 25 14:54 libTable.so
792776 -rw-rw-r-- 1 physics physics 1026 Jun 25 14:58 libThread.rootmap
792696 -rwxrwxr-x 1 physics physics 373695 Jun 25 14:13 libThread.so
792831 -rw-rw-r-- 1 physics physics 21546 Jun 25 14:58 libTMVA.rootmap
792760 -rwxrwxr-x 1 physics physics 6863419 Jun 25 14:58 libTMVA.so
792789 -rw-rw-r-- 1 physics physics 10325 Jun 25 14:58 libTreePlayer.rootmap
792714 -rwxrwxr-x 1 physics physics 2015289 Jun 25 14:25 libTreePlayer.so
792782 -rw-rw-r-- 1 physics physics 4576 Jun 25 14:58 libTree.rootmap
792707 -rwxrwxr-x 1 physics physics 2538339 Jun 25 14:20 libTree.so
792791 -rw-rw-r-- 1 physics physics 2672 Jun 25 14:58 libTreeViewer.rootmap
792716 -rwxrwxr-x 1 physics physics 1056998 Jun 25 14:26 libTreeViewer.so
795696 -rw-rw-r-- 1 physics physics 581 Jun 25 14:58 libUnuran.rootmap
795697 -rwxrwxr-x 1 physics physics 1126182 Jun 25 14:43 libUnuran.so
792774 -rw-rw-r-- 1 physics physics 228 Jun 25 14:58 libvalarrayDict.rootmap
792694 -rwxrwxr-x 1 physics physics 25477 Jun 25 14:13 libvalarrayDict.so
792765 -rw-rw-r-- 1 physics physics 1050 Jun 25 14:58 libvectorDict.rootmap
792685 -rwxrwxr-x 1 physics physics 194278 Jun 25 14:13 libvectorDict.so
792799 -rw-rw-r-- 1 physics physics 534 Jun 25 14:58 libVMC.rootmap
792724 -rwxrwxr-x 1 physics physics 335717 Jun 25 14:28 libVMC.so
792822 -rw-rw-r-- 1 physics physics 77 Jun 25 14:58 libX3d.rootmap
792747 -rwxrwxr-x 1 physics physics 185064 Jun 25 14:34 libX3d.so
792805 -rw-rw-r-- 1 physics physics 396 Jun 25 14:58 libXMLIO.rootmap
792730 -rwxrwxr-x 1 physics physics 610395 Jun 25 14:29 libXMLIO.so
795698 -rw-rw-r-- 1 physics physics 360 Jun 25 14:58 libXMLParser.rootmap
795699 -rwxrwxr-x 1 physics physics 189872 Jun 25 14:40 libXMLParser.so
792755 -rw-rw-r-- 1 physics physics 4536 Jun 25 14:44 PyCintex.py
795651 -rw-rw-r-- 1 physics physics 4920 Jun 25 14:44 PyCintex.pyc
795652 -rw-rw-r-- 1 physics physics 4920 Jun 25 14:44 PyCintex.pyo
792851 drwxrwxr-x 3 physics physics 4096 Jun 25 14:58 python
795653 -rwxrwxr-x 1 physics physics 22574 Jun 25 14:40 ROOT.py
795654 -rw-rw-r-- 1 physics physics 18221 Jun 25 14:40 ROOT.pyc
795655 -rw-rw-r-- 1 physics physics 18221 Jun 25 14:40 ROOT.pyo
796291 -rw-rw-r-- 1 physics physics 21968 Jun 25 13:33 ROOTwriter.py
796292 -rw-rw-r-- 1 physics physics 11603 Jun 25 13:33 writer.py
/usr/local/root/lib/python:
total 20
792851 drwxrwxr-x 3 physics physics 4096 Jun 25 14:58 .
791161 drwxrwxr-x 3 physics physics 12288 Jun 25 14:59 …
1709193 drwxrwxr-x 2 physics physics 4096 Jun 25 14:58 genreflex
/usr/local/root/lib/python/genreflex:
total 440
1709193 drwxrwxr-x 2 physics physics 4096 Jun 25 14:58 .
792851 drwxrwxr-x 3 physics physics 4096 Jun 25 14:58 …
1709195 -rw-rw-r-- 1 physics physics 37481 Jun 25 14:58 gccdemangler.py
1709317 -rw-rw-r-- 1 physics physics 32481 Jun 25 14:58 gccdemangler.pyc
1709194 -rw-rw-r-- 1 physics physics 16 Jun 25 14:58 gccxmlpath.py
1709315 -rw-rw-r-- 1 physics physics 147 Jun 25 14:58 gccxmlpath.pyc
1709196 -rw-rw-r-- 1 physics physics 1441 Jun 25 14:58 gencapa.py
1709319 -rw-rw-r-- 1 physics physics 1278 Jun 25 14:58 gencapa.pyc
1709197 -rw-rw-r-- 1 physics physics 134284 Jun 25 14:58 gendict.py
1709314 -rw-rw-r-- 1 physics physics 103264 Jun 25 14:58 gendict.pyc
1709198 -rw-rw-r-- 1 physics physics 4047 Jun 25 14:58 genheader.py
1709316 -rw-rw-r-- 1 physics physics 5616 Jun 25 14:58 genheader.pyc
1709199 -rw-rw-r-- 1 physics physics 18641 Jun 25 14:58 genreflex.py
1709318 -rw-rw-r-- 1 physics physics 15733 Jun 25 14:58 genreflex.pyc
1709200 -rw-rw-r-- 1 physics physics 4844 Jun 25 14:58 genreflex-rootcint.py
1709313 -rw-rw-r-- 1 physics physics 5651 Jun 25 14:58 genreflex-rootcint.pyc
1709201 -rw-rw-r-- 1 physics physics 2384 Jun 25 14:58 genrootmap.py
1709321 -rw-rw-r-- 1 physics physics 2180 Jun 25 14:58 genrootmap.pyc
1709202 -rw-rw-r-- 1 physics physics 19038 Jun 25 14:58 selclass.py
1709320 -rw-rw-r-- 1 physics physics 13861 Jun 25 14:58 selclass.pyc

Please do NOT execute “source /…/bin/thisroot.sh” and try:

which root-config
type root-config
echo $PATH
echo $LD_LIBRARY_PATH
locate libCore

One needs to understand where does this “root-config” that returns “/usr/local/root/” come from.

I suspect this is the problem.
In general, you should make sure that you have “completely removed” (i.e. use “remove with any associated configuration files”) all standard Ubuntu’s ROOT packages, before trying to build your own ROOT version.

In a new terminal, without running “source /…/bin/thisroot.sh,” i got:

physics@physics-VirtualBox:~$ which root-config
/usr/local/root/bin/root-config
physics@physics-VirtualBox:~$ type root-config
root-config is /usr/local/root/bin/root-config
physics@physics-VirtualBox:~$ echo $PATH
/usr/local/root/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
physics@physics-VirtualBox:~$ echo $LD_LIBRARY_PATH
physics@physics-VirtualBox:~$ locate libCore
/home/physics/.local/share/Trash/files/root/lib/libCore.rootmap
/home/physics/.local/share/Trash/files/root/lib/libCore.so
/home/physics/oldfiles/analysis10023/root/lib/libCore.rootmap
/home/physics/oldfiles/analysis10023/root/lib/libCore.so
/home/physics/oldfiles/analysis10023/root/lib/libCore.so.5
/home/physics/oldfiles/analysis10023/root/lib/libCore.so.5.26
/home/physics/oldfiles/physics/root/lib/libCore.rootmap
/home/physics/oldfiles/physics/root/lib/libCore.so
/home/physics/root-v5-34/lib/libCore.rootmap
/home/physics/root-v5-34/lib/libCore.so
/home/physics/root-v5-34/lib/libCore.so.5
/home/physics/root-v5-34/lib/libCore.so.5.34
/usr/local/root-v5-34-00-patches/lib/libCore.rootmap
/usr/local/root-v5-34-00-patches/lib/libCore.so

I tried building from scratch twice so far, but didn’t delete the files from the first time. That is the root you’re seeing in /usr/local/. The new one is in /home/physics/root-v5-34. So are you saying I should delete all the files from the first time I tried building?

You should make sure that all “existing” ROOT versions are NOT “visible” when you build new ROOT.
That means, “unset ROOTSYS”, remove any references to “/usr/local/root” ("/usr/local/root-v5-34-00-patches") from PATH and LD_LIBRARY_PATH and so on (e.g. remove any references from your “.profile”, “.bash_profile”, “.bashrc”, and so on and then re-login to make sure that everything is gone).
You could also try to (just to make sure that they “disappear”):
mv /usr/local/root /usr/local/root.orig
mv /usr/local/root-v5-34-00-patches /usr/local/root-v5-34-00-patches.orig
Also, always remove the “destination subdirectory” (so that there are no remnants from any previous trials) and start with a “fresh” source code (i.e. remove the “source subdirectory” and unpack the source code again).

BTW. I don’t understand why “locate libCore” did not return any “/usr/local/root/lib/libCore.*”. If “/usr/local/root” is a symbolic link to “/usr/local/root-v5-34-00-patches”, make sure that this link “disappears”, too. (The same concerns any other symbolic links that point to anywhere in the “old” ROOT.)

Have you succeeded?
If not, I’ve got another idea which may help. Try to configure your ROOT using:
./configure --enable-explicitlink --enable-soversion --enable-rpath --all > configure.out.txt 2>&1