> On 17. Jul 2019, at 20:11, Robert Vollmert <r...@vllmrt.net> wrote:
>
>
>
>> On 17. Jul 2019, at 19:57, Mark H Weaver <m...@netris.org> wrote:
>>
>> Hi Robert,
>>
>> Robert Vollmert <r...@vllmrt.net> writes:
>>
>>> * module/system/repl/debug.scm (print-frame): Print full object if
>>> width keyword is #f.
>>> * libguile/backtrace.c (display_backtrace_body): Call print-frames
>>> with #:width #f.
>>> ---
>>>
>>> This change was prompted by recent discussion on the Guix lists:
>>> https://lists.gnu.org/archive/html/guix-devel/2019-07/msg00207.html
>>> In Guix, the truncation of stack traces frequently obscures
>>> important information due to the long filenames.
>>
>> I'm sympathetic to this problem, but simply disabling the truncated
>> printing during backtraces is not workable. It is quite often the case
>> that some of the structures printed in backtraces are *huge*, or even
>> cyclic.
>>
>> Have you tried setting the COLUMNS environment variable to a larger
>> value? I'd prefer a solution along those lines, where the user can set
>> an environment variable to ask for less truncation in backtraces.
>
> Defaulting to something longer than 80 might be workable, say 250?
>
> I don’t think that it should be necessary to set an environment variable
> to get usable stack traces…
I’d like to add that the current code to determine terminal width
seems to be broken. COLUMNS is a bash-local variable, it’s not typically
set anywhere as an environment variable.
Some ways to get actual terminal size:
$ tput cols # from ncurses
80
$ stty size # from coreutils
25 80
Though it’s unclear how these work in non-interactive situations.
