TPython::Prompt() problem since ROOT 5.25.02

[yesw2000]

Hi,

TPython::Prompt() in ROOT 5.25.02 and later would crash whenever an input is entered under python prompt “>>>”.

[quote]root [0] TPython::Prompt();

print 2

*** Break *** segmentation violation

…

The lines below might hint at the cause of the crash.
If they do not help you then please submit a bug report at
root.cern.ch/bugs. Please post the ENTIRE stack trace
from above as an attachment in addition to anything else
that might help us fixing this issue.

#10 0xf547840e in call_readline (sys_stdin=0xf7022420, sys_stdout=0xf70224c0,
prompt=0xf543b174 ">>> ") at /build/LCG/Python-2.5/Modules/readline.c:890
#11 0xf5d300cb in PyOS_Readline (sys_stdin=0xf7022420, sys_stdout=0xf70224c0,
prompt=0xf543b174 ">>> ") at Parser/myreadline.c:208
#12 0xf5d31390 in tok_nextc (tok=0x9961130) at Parser/tokenizer.c:779
#13 0xf5d31b3c in PyTokenizer_Get (tok=0x9961130, p_start=0xffc70bf4,
p_end=0xffc70bf8) at Parser/tokenizer.c:1126
#14 0xf5d2d4e3 in parsetok (tok=0x9961130, g=, start=256,
err_ret=0xffc70c40, flags=) at Parser/parsetok.c:135
#15 0xf5dd05d6 in PyParser_ASTFromFile (fp=0xf7022420, filename=0xf6cab78c “”,
start=256, ps1=0xf543b174 ">>> ", ps2=0xf5434df4 "… ", flags=0xffc70cf8,
errcode=0xffc70cb8, arena=0x9c033d8) at Python/pythonrun.c:1373
#16 0xf5dd1503 in PyRun_InteractiveOneFlags (fp=0xf7022420,
filename=0xf6cab78c “”, flags=0xffc70cf8) at Python/pythonrun.c:763
#17 0xf5dd171b in PyRun_InteractiveLoopFlags (fp=0xf7022420,
filename=0xf6cab78c “”, flags=0xffc70cf8) at Python/pythonrun.c:714
#18 0xf6c95883 in TPython::Prompt ()
from /afs/usatlas.bnl.gov/cernsw/lcg/app/releases/ROOT/5.25.04/slc4_ia32_gcc3
4/root/lib/libPyROOT.so

[/quote]

I tried ROOT 5.25.02, 5.25.04 and 5.26.00, the same problem. But there is no such a problem with ROOT 5.24.00. I noticed one difference between version 5.24.00 and the others. In 5.24.00, the “TPython::Prompt()” is shown in mono, while in 5.25.02 and the others it is shown in color, something like “[color=blue]TPython[/color]::Promptcolor=cyan[/color]”.

–Shuwei

[wlav]

Shuwei,

works fine for me … which platform are you running on, and is “editline” enabled (it is by default)?

Cheers,
Wim

[yesw2000]

Hi Wim,

I am running in SL©5. I also tried SL4 at BNL and SLC5 at CERN, the same problem.

lxplus232% which root
/afs/cern.ch/sw/lcg/app/releases/ROOT/5.25.02/slc4_ia32_gcc34/root/bin/root

lxplus232% root -l
root [0] TPython::Prompt();

print 2

*** Break *** segmentation violation
#0 0xffffe410 in __kernel_vsyscall ()
#1 0x0072e4b3 in __waitpid_nocancel () from /lib/tls/libc.so.6
#2 0x006d7779 in do_system () from /lib/tls/libc.so.6
#3 0x0081698d in system () from /lib/tls/libpthread.so.0
#4 0xf7b4a02f in TUnixSystem::Exec ()
#5 0xf7b4fcff in TUnixSystem::StackTrace ()
#6 0xf7b4c6ca in TUnixSystem::DispatchSignals ()
#7 0xf7b4c758 in SigHandler ()
#8 0xf7b4b9d5 in sighandler ()
#9
#10 0xf588080b in call_readline (sys_stdin=0x7ce720, sys_stdout=0x7ce5c0,
#11 0xf61cf3e3 in PyOS_Readline (sys_stdin=0x7ce720, sys_stdout=0x7ce5c0,
#12 0xf61d0780 in tok_nextc (tok=0x85dff00) at Parser/tokenizer.c:790
#13 0xf61d0fc8 in PyTokenizer_Get (tok=0x85dff00, p_start=0xfffe2a94,
#14 0xf61cc7b6 in parsetok (tok=0x85dff00, g=Variable “g” is not available.
#15 0xf6271416 in PyParser_ASTFromFile (fp=0x7ce720, filename=0xf7138f2c “”,
#16 0xf6272343 in PyRun_InteractiveOneFlags (fp=0x7ce720,
#17 0xf627255b in PyRun_InteractiveLoopFlags (fp=0x7ce720,
#18 0xf712306b in TPython::Prompt ()
#19 0xf712f3d0 in G__G__PyROOT_198_0_7 ()
#20 0xf73d503b in Cint::G__ExceptionWrapper ()
#21 0xf746cde0 in G__execute_call ()
#22 0xf746d0f2 in G__call_cppfunc ()
#23 0xf744efdb in G__interpret_func ()
#24 0xf743b61c in G__getfunction ()
#25 0xf741ea6c in G__getitem ()
#26 0xf74227b9 in G__getexpr ()
#27 0xf74a04fd in G__exec_statement ()
#28 0xf740bfa4 in G__exec_tempfile_core ()
#29 0xf740d2e7 in G__exec_tempfile_fp ()
#30 0xf74aa44b in G__process_cmd ()
#31 0xf7b37f67 in TCint::ProcessLine ()
#32 0xf7a6ac1a in TApplication::ProcessLine ()
#33 0xf71d7d4b in TRint::HandleTermInput ()
#34 0xf71d5cac in TTermInputHandler::Notify ()
#35 0xf71d866a in TTermInputHandler::ReadNotify ()
#36 0xf7b4895a in TUnixSystem::CheckDescriptors ()
#37 0xf7b4cba8 in TUnixSystem::DispatchOneEvent ()
#38 0xf7ac7818 in TSystem::InnerLoop ()
#39 0xf7ac75df in TSystem::Run ()
#40 0xf7a6add6 in TApplication::Run ()
#41 0xf71d6592 in TRint::Run ()
#42 0x08048d46 in main ()

What is “editline”? And how to check if it is enabled? By the way the same python is used for ROOT 5.24.00 and 5.25.04.

–Shuwei

[wlav]

Shuwei,

“root-config --config” will yield the configure CLI options, and yes, editline is enabled. At issue is that editline is a readline alternative (different license) and it duplicates several symbols (there’s a readline.cxx in root/core/editline/src). Presumably they clash.

Since editline is inside libCore.so, its loading can’t be helped, meaning that the only solution I can see is to strip readline out of ROOT.py (which also means that there’s no python-side line editing available).

Right now, I can’t think of a better answer …

Cheers,
Wim

[Axel]

Hi,

I’ll try to hide these symbols, they need not be accessible outside libCore anyway. Will post when done.

Cheers, Axel.

[Axel]

Hi,

fixed in v5-26-00-patches and the trunk. Thanks for your report and Wim’s diagnosis!

Cheers, Axel.