I have a problem with TTree->Draw() in ROOT 6.12 but not in 6.10
I did a simple example with this test.dat file:
1 5
2 10
3 15
First, the example that works using ROOT 6.10:
$ rootn.exe
------------------------------------------------------------
| Welcome to ROOT 6.10/09 [http://root.cern.ch](http://root.cern.ch/) |
| (c) 1995-2017, The ROOT Team |
| Built for linuxx8664gcc |
| From tag , 16 October 2017 |
| Try '.help', '.demo', '.license', '.credits', '.quit'/'.q' |
------------------------------------------------------------
root [0] TTree *t = new TTree("data","title")
(TTree *) 0x2768a88
root [1] t->ReadFile("test.dat","X/I:Y/I")
(long long) 3
root [2] t->Print()
******************************************************************************
*Tree :data : title *
*Entries : 3 : Total = 1526 bytes File Size = 0 *
* : : Tree compression factor = 1.00 *
******************************************************************************
*Br 0 :X : X/I *
*Entries : 3 : Total Size= 622 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
*............................................................................*
*Br 1 :Y : Y/I *
*Entries : 3 : Total Size= 622 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
*............................................................................*
root [3] t->Scan()
************************************
* Row * X * Y *
************************************
* 0 * 1 * 5 *
* 1 * 2 * 10 *
* 2 * 3 * 15 *
************************************
(long long) 3
root [4] t->Draw("Y")
Info in <TCanvas::MakeDefCanvas>: created default TCanvas with name c1
root [5] .q
Then, the identical thing in ROOT 6.12:
$ rootn.exe
------------------------------------------------------------
| Welcome to ROOT 6.12/07 [http://root.cern.ch](http://root.cern.ch/) |
| (c) 1995-2017, The ROOT Team |
| Built for linuxx8664gcc |
| From tag , 9 February 2018 |
| Try '.help', '.demo', '.license', '.credits', '.quit'/'.q' |
------------------------------------------------------------
root [0] TTree *t = new TTree("data","title")
(TTree *) 0x2ee6948
root [1] t->ReadFile("test.dat","X/I:Y/I")
(long long) 3
root [2] t->Print()
******************************************************************************
*Tree :data : title *
*Entries : 3 : Total = 1559 bytes File Size = 0 *
* : : Tree compression factor = 1.00 *
******************************************************************************
*Br 0 :X : X/I *
*Entries : 3 : Total Size= 633 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
*............................................................................*
*Br 1 :Y : Y/I *
*Entries : 3 : Total Size= 633 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
*............................................................................*
root [3] t->Scan()
************************************
* Row * X * Y *
************************************
* 0 * 1 * 5 *
* 1 * 2 * 10 *
* 2 * 3 * 15 *
************************************
(long long) 3
root [4] t->Draw("Y")
*** Break *** segmentation violation
===========================================================
There was a crash.
This is the entire stack trace of all threads:
===========================================================
#0 0x00007effbd6a689e in waitpid () from /lib64/libc.so.6
#1 0x00007effbd6384e9 in do_system () from /lib64/libc.so.6
I’ve verified that I can then switch back to ROOT 6.10 and these steps again run correctly.