Re: [Bug-readline] readline bug with backgrounded process?

[Thomas Klausner]

On Mon, Apr 14, 2014 at 10:06:44AM -0400, Chet Ramey wrote:
> On 4/13/14, 6:46 PM, Thomas Klausner wrote:
> > Hi!
> > 
> > Since a couple of weeks ago, gnucash as installed by pkgsrc on
> > NetBSD-6.99.40/amd64 doesn't start in the background any longer for
> > me.
> > 
> > It looks like this (in zsh):
> 
> It looks like gnucash, when linked with readline, attempts to write to the
> controlling terminal and gets a SIGTTOU.
> 
> >> gnucash &
> > [1] 8065
> >>
> > [1]  + suspended (tty output)  gnucash
> >> fg
> > [1]  + continued  gnucash
> > Found Finance::Quote version 1.18
> > (runs)
> 
> And it appears that the above message about `Quote version 1.18' is what it
> tries to write.
> 
> I suppose it could be readline reacting to the SIGTTOU and calling the
> signal hook, but I doubt that python has a signal hook assigned.  If
> there's no signal hook, readline just passes the signal through to the
> calling application.  In the case of SIGTTOU, unless the calling
> application is ignoring it, the process will be stopped.
> 
> It might be useful to get a stack traceback from the gnucash process
> when it gets a SIGTTOU.

I've installed a signal handler catching SIGTTOU and calling abort()
in the gnucash binary.

Here's the backtrace:
(gdb) bt
#0  0x00007f7fdcb0e12a in _lwp_kill () from /usr/lib/libc.so.12
#1  0x00007f7fdcb0ddb5 in abort () at 
/archive/foreign/src/lib/libc/stdlib/abort.c:74
#2  0x0000000000405ea0 in debug_step (signal=22) at gnucash-bin.c:565
#3  <signal handler called>
#4  0x00007f7fdcad1b08 in ioctl () from /usr/lib/libc.so.12
#5  0x00007f7fc821a0fa in set_winsize () from /usr/pkg/lib/libreadline.so.6
#6  0x00007f7fc821a351 in rltty_set_default_bindings () from 
/usr/pkg/lib/libreadline.so.6
#7  0x00007f7fc8216599 in rl_initialize () from /usr/pkg/lib/libreadline.so.6
#8  0x00007f7fc8603656 in initreadline () from 
/usr/pkg/lib/python2.7/lib-dynload/readline.so
#9  0x00007f7fd5edefc3 in _PyImport_LoadDynamicModule () from 
/usr/pkg/lib/libpython2.7.so.1.0
#10 0x00007f7fd5edd3e8 in import_submodule () from 
/usr/pkg/lib/libpython2.7.so.1.0
#11 0x00007f7fd5edd695 in load_next () from /usr/pkg/lib/libpython2.7.so.1.0
#12 0x00007f7fd5edde92 in PyImport_ImportModuleLevel () from 
/usr/pkg/lib/libpython2.7.so.1.0
#13 0x00007f7fd5ec648b in builtin___import__ () from 
/usr/pkg/lib/libpython2.7.so.1.0
#14 0x00007f7fd5e46a98 in PyObject_Call () from /usr/pkg/lib/libpython2.7.so.1.0
#15 0x00007f7fd5ec7d40 in PyEval_CallObjectWithKeywords () from 
/usr/pkg/lib/libpython2.7.so.1.0
#16 0x00007f7fd5ecae83 in PyEval_EvalFrameEx () from 
/usr/pkg/lib/libpython2.7.so.1.0
#17 0x00007f7fd5ecde47 in PyEval_EvalCodeEx () from 
/usr/pkg/lib/libpython2.7.so.1.0
#18 0x00007f7fd5ecdef2 in PyEval_EvalCode () from 
/usr/pkg/lib/libpython2.7.so.1.0
#19 0x00007f7fd5edc6a3 in PyImport_ExecCodeModuleEx () from 
/usr/pkg/lib/libpython2.7.so.1.0
#20 0x00007f7fd5edc8d5 in load_source_module () from 
/usr/pkg/lib/libpython2.7.so.1.0
#21 0x00007f7fd5edd3e8 in import_submodule () from 
/usr/pkg/lib/libpython2.7.so.1.0
#22 0x00007f7fd5edd60a in load_next () from /usr/pkg/lib/libpython2.7.so.1.0
#23 0x00007f7fd5eddec7 in PyImport_ImportModuleLevel () from 
/usr/pkg/lib/libpython2.7.so.1.0
#24 0x00007f7fd5ec648b in builtin___import__ () from 
/usr/pkg/lib/libpython2.7.so.1.0
#25 0x00007f7fd5e46a98 in PyObject_Call () from /usr/pkg/lib/libpython2.7.so.1.0
#26 0x00007f7fd5ec7d40 in PyEval_CallObjectWithKeywords () from 
/usr/pkg/lib/libpython2.7.so.1.0
#27 0x00007f7fd5ecae83 in PyEval_EvalFrameEx () from 
/usr/pkg/lib/libpython2.7.so.1.0
#28 0x00007f7fd5ecde47 in PyEval_EvalCodeEx () from 
/usr/pkg/lib/libpython2.7.so.1.0
#29 0x00007f7fd5ecdef2 in PyEval_EvalCode () from 
/usr/pkg/lib/libpython2.7.so.1.0
#30 0x00007f7fd5ee4d6f in run_mod () from /usr/pkg/lib/libpython2.7.so.1.0
#31 0x00007f7fd5ee5cd7 in PyRun_FileExFlags () from 
/usr/pkg/lib/libpython2.7.so.1.0
#32 0x00007f7fd5ee6cdd in PyRun_SimpleFileExFlags () from 
/usr/pkg/lib/libpython2.7.so.1.0
#33 0x00007f7fd6a00fac in libgncmod_python_gnc_module_init () from 
/usr/pkg/lib/gnucash/libgncmod-python.so
#34 0x00007f7fe9203001 in gnc_module_load_common () from 
/usr/pkg/lib/libgnc-module.so.0
#35 0x0000000000405ba4 in load_gnucash_modules () at gnucash-bin.c:477
#36 0x0000000000405efd in inner_main (closure=0x0, argc=1, argv=0x7f7fffffd568) 
at gnucash-bin.c:584
#37 0x00007f7fe865fbf3 in invoke_main_func () from /usr/pkg/lib/libguile.so.17
#38 0x00007f7fe863b6da in c_body () from /usr/pkg/lib/libguile.so.17
#39 0x00007f7fe8696923 in scm_c_catch () from /usr/pkg/lib/libguile.so.17
#40 0x00007f7fe863bbdc in scm_i_with_continuation_barrier () from 
/usr/pkg/lib/libguile.so.17
#41 0x00007f7fe863bc60 in scm_c_with_continuation_barrier () from 
/usr/pkg/lib/libguile.so.17
#42 0x00007f7fe8695148 in scm_i_with_guile_and_parent () from 
/usr/pkg/lib/libguile.so.17
#43 0x00007f7fe865fd10 in scm_boot_guile () from /usr/pkg/lib/libguile.so.17
#44 0x0000000000406458 in main (argc=1, argv=0x7f7fffffd568) at 
gnucash-bin.c:780

What does this tell you?
 Thomas