R devel - Sep 2020 - [External] Re: Operations with long altrep vectors cause segfaults on Windows

On Tue, Sep 8, 2020 at 11:44 PM Jeroen Ooms <jeroenooms at gmail.com>
wrote:
>
> On Tue, Sep 8, 2020 at 5:20 PM Tomas Kalibera <tomas.kalibera at
gmail.com> wrote:
> >
> > On 9/8/20 4:48 PM, Hugh Parsonage wrote:
> > > Unfortunately I only get
> > >
> > > [Thread 21752.0x4aa8 exited with code 3221225477]
> > > [Thread 21752.0x4514 exited with code 3221225477]
> > > [Thread 21752.0x3f10 exited with code 3221225477]
> > > [Inferior 1 (process 21752) exited with code 030000000005]
> > >
> > > (I'm guessing I would need to build an instrumented version
of R, or
> > > can R be debugged using gdb with an off-the-shelf installation?)
> >
> > No, the default build lacks debug symbols. You need a build with debug
> > symbols, and if you can reproduce in a build without compiler
> > optimizations (-O0), the backtrace may be easier to interpret. Some
bugs
> > however "disappear" when optimizations are disabled. You can
build R
> > from source (and there may be debug builds provided by someone else
> > (Jeroen?)).
>
> Debug builds for each revision are available from
> https://r-devel.github.io . To download the installer you need to
> click the github icon in the last column in the table. You need to be
> signed in with a (free) Github account in order to download builds
> (artifacts) from Github actions. It will show download links for both
> the regular installer and installer with debug symbols.
>
> In other news, the https://r-devel.github.io table also shows that the
> fix that martin committed is segfaulting on 32-bit.
Sorry that was inaccurate, it is not segfaulting at all, but the unit
test is raising an error on 32-bit.

I am unable to set break or use gdb with any success when I use that version.

On linux I would do R -d gdb but this gives "unknown option '-d'
"
while gdb R.exe (in the same directory as the debug version) gives the
same output as before.

I'm happy to help but I appreciate this list might not be the best
place to get a tutorial on using gdb on Windows.

On Wed, 9 Sep 2020 at 07:47, Jeroen Ooms <jeroenooms at gmail.com>
wrote:
>
> On Tue, Sep 8, 2020 at 11:44 PM Jeroen Ooms <jeroenooms at gmail.com>
wrote:
> >
> > On Tue, Sep 8, 2020 at 5:20 PM Tomas Kalibera <tomas.kalibera at
gmail.com> wrote:
> > >
> > > On 9/8/20 4:48 PM, Hugh Parsonage wrote:
> > > > Unfortunately I only get
> > > >
> > > > [Thread 21752.0x4aa8 exited with code 3221225477]
> > > > [Thread 21752.0x4514 exited with code 3221225477]
> > > > [Thread 21752.0x3f10 exited with code 3221225477]
> > > > [Inferior 1 (process 21752) exited with code 030000000005]
> > > >
> > > > (I'm guessing I would need to build an instrumented
version of R, or
> > > > can R be debugged using gdb with an off-the-shelf
installation?)
> > >
> > > No, the default build lacks debug symbols. You need a build with
debug
> > > symbols, and if you can reproduce in a build without compiler
> > > optimizations (-O0), the backtrace may be easier to interpret.
Some bugs
> > > however "disappear" when optimizations are disabled.
You can build R
> > > from source (and there may be debug builds provided by someone
else
> > > (Jeroen?)).
> >
> > Debug builds for each revision are available from
> > https://r-devel.github.io . To download the installer you need to
> > click the github icon in the last column in the table. You need to be
> > signed in with a (free) Github account in order to download builds
> > (artifacts) from Github actions. It will show download links for both
> > the regular installer and installer with debug symbols.
> >
> > In other news, the https://r-devel.github.io table also shows that the
> > fix that martin committed is segfaulting on 32-bit.
>
> Sorry that was inaccurate, it is not segfaulting at all, but the unit
> test is raising an error on 32-bit.

On 9/9/20 8:48 AM, Hugh Parsonage wrote:
> I am unable to set break or use gdb with any success when I use that
version.
>
> On linux I would do R -d gdb but this gives "unknown option
'-d' "
> while gdb R.exe (in the same directory as the debug version) gives the
> same output as before.
>
> I'm happy to help but I appreciate this list might not be the best
> place to get a tutorial on using gdb on Windows.
Essentially, the steps are: build with DEBUG=T (to have debug symbols), 
possibly updating EOPTS in MkRules.local to disable optimizations, then 
run gdb loading RGui, "set solib-search-path", run RGui from gdb. Then
you can break to debugger from RGui menu, or just run the code that 
segfaults, and you get to gdb and can print the stacktrace, etc. You can 
find some information in rw-FAQ (R for Windows FAQ), but yes, it is 
harder than on Linux. We can take care of this report, but of course in 
the longer term it would help if more people could take their time to 
setup debugging and analyze bugs even on Windows.

Tomas
>
> On Wed, 9 Sep 2020 at 07:47, Jeroen Ooms <jeroenooms at gmail.com>
wrote:
>> On Tue, Sep 8, 2020 at 11:44 PM Jeroen Ooms <jeroenooms at
gmail.com> wrote:
>>> On Tue, Sep 8, 2020 at 5:20 PM Tomas Kalibera <tomas.kalibera at
gmail.com> wrote:
>>>> On 9/8/20 4:48 PM, Hugh Parsonage wrote:
>>>>> Unfortunately I only get
>>>>>
>>>>> [Thread 21752.0x4aa8 exited with code 3221225477]
>>>>> [Thread 21752.0x4514 exited with code 3221225477]
>>>>> [Thread 21752.0x3f10 exited with code 3221225477]
>>>>> [Inferior 1 (process 21752) exited with code 030000000005]
>>>>>
>>>>> (I'm guessing I would need to build an instrumented
version of R, or
>>>>> can R be debugged using gdb with an off-the-shelf
installation?)
>>>> No, the default build lacks debug symbols. You need a build
with debug
>>>> symbols, and if you can reproduce in a build without compiler
>>>> optimizations (-O0), the backtrace may be easier to interpret.
Some bugs
>>>> however "disappear" when optimizations are disabled.
You can build R
>>>> from source (and there may be debug builds provided by someone
else
>>>> (Jeroen?)).
>>> Debug builds for each revision are available from
>>> https://r-devel.github.io . To download the installer you need to
>>> click the github icon in the last column in the table. You need to
be
>>> signed in with a (free) Github account in order to download builds
>>> (artifacts) from Github actions. It will show download links for
both
>>> the regular installer and installer with debug symbols.
>>>
>>> In other news, the https://r-devel.github.io table also shows that
the
>>> fix that martin committed is segfaulting on 32-bit.
>> Sorry that was inaccurate, it is not segfaulting at all, but the unit
>> test is raising an error on 32-bit.

On 9/8/20 11:47 PM, Jeroen Ooms wrote:
> On Tue, Sep 8, 2020 at 11:44 PM Jeroen Ooms <jeroenooms at gmail.com>
wrote:
>> On Tue, Sep 8, 2020 at 5:20 PM Tomas Kalibera <tomas.kalibera at
gmail.com> wrote:
>>> On 9/8/20 4:48 PM, Hugh Parsonage wrote:
>>>> Unfortunately I only get
>>>>
>>>> [Thread 21752.0x4aa8 exited with code 3221225477]
>>>> [Thread 21752.0x4514 exited with code 3221225477]
>>>> [Thread 21752.0x3f10 exited with code 3221225477]
>>>> [Inferior 1 (process 21752) exited with code 030000000005]
>>>>
>>>> (I'm guessing I would need to build an instrumented version
of R, or
>>>> can R be debugged using gdb with an off-the-shelf
installation?)
>>> No, the default build lacks debug symbols. You need a build with
debug
>>> symbols, and if you can reproduce in a build without compiler
>>> optimizations (-O0), the backtrace may be easier to interpret. Some
bugs
>>> however "disappear" when optimizations are disabled. You
can build R
>>> from source (and there may be debug builds provided by someone else
>>> (Jeroen?)).
>> Debug builds for each revision are available from
>> https://r-devel.github.io . To download the installer you need to
>> click the github icon in the last column in the table. You need to be
>> signed in with a (free) Github account in order to download builds
>> (artifacts) from Github actions. It will show download links for both
>> the regular installer and installer with debug symbols.
>>
>> In other news, the https://r-devel.github.io table also shows that the
>> fix that martin committed is segfaulting on 32-bit.
> Sorry that was inaccurate, it is not segfaulting at all, but the unit
> test is raising an error on 32-bit.
Now fixed, the test needs to be run only on 64-bit builds where such 
long vectors/sequences are allowed.

Tomas

I can confirm the segmentation fault does not occur as of r79170.

On Wed, 9 Sep 2020 at 19:06, Tomas Kalibera <tomas.kalibera at gmail.com>
wrote:
>
> On 9/8/20 11:47 PM, Jeroen Ooms wrote:
> > On Tue, Sep 8, 2020 at 11:44 PM Jeroen Ooms <jeroenooms at
gmail.com> wrote:
> >> On Tue, Sep 8, 2020 at 5:20 PM Tomas Kalibera <tomas.kalibera
at gmail.com> wrote:
> >>> On 9/8/20 4:48 PM, Hugh Parsonage wrote:
> >>>> Unfortunately I only get
> >>>>
> >>>> [Thread 21752.0x4aa8 exited with code 3221225477]
> >>>> [Thread 21752.0x4514 exited with code 3221225477]
> >>>> [Thread 21752.0x3f10 exited with code 3221225477]
> >>>> [Inferior 1 (process 21752) exited with code 030000000005]
> >>>>
> >>>> (I'm guessing I would need to build an instrumented
version of R, or
> >>>> can R be debugged using gdb with an off-the-shelf
installation?)
> >>> No, the default build lacks debug symbols. You need a build
with debug
> >>> symbols, and if you can reproduce in a build without compiler
> >>> optimizations (-O0), the backtrace may be easier to interpret.
Some bugs
> >>> however "disappear" when optimizations are disabled.
You can build R
> >>> from source (and there may be debug builds provided by someone
else
> >>> (Jeroen?)).
> >> Debug builds for each revision are available from
> >> https://r-devel.github.io . To download the installer you need to
> >> click the github icon in the last column in the table. You need to
be
> >> signed in with a (free) Github account in order to download builds
> >> (artifacts) from Github actions. It will show download links for
both
> >> the regular installer and installer with debug symbols.
> >>
> >> In other news, the https://r-devel.github.io table also shows that
the
> >> fix that martin committed is segfaulting on 32-bit.
> > Sorry that was inaccurate, it is not segfaulting at all, but the unit
> > test is raising an error on 32-bit.
>
> Now fixed, the test needs to be run only on 64-bit builds where such
> long vectors/sequences are allowed.
>
> Tomas
>