Feature #9805: Backtrace for SystemStackError

• Status: Closed
• Assignee: -
• Target version: -

[sawa (Tsuyoshi Sawada)]

The following code:

def a; a end
begin
  a
rescue => e
puts  e.backtrace.inspect
end

only returns a single line of backtrace like:

/tmp/scratch:3:in `a'

but this is not helpful when debugging. It would be better if some limit be set by configuration, and the backtrace is displayed as far as possible within the limit, so the case above would become:

/tmp/scratch:3:in `a'
/tmp/scratch:3:in `a'
/tmp/scratch:3:in `a'
... # repeated as many times as the limit set
/tmp/scratch:3:in `a'

I believe the same question was asked here: https://bugs.ruby-lang.org/issues/6216, but the code posted by the poster was unnecessarily long and complex that the intent was not clear to many people.

[nobu (Nobuyoshi Nakada)]

• Is duplicate of Feature #6216: SystemStackError backtraces should not be reduced to one line added

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset r46502.

---

Backtrace for SystemStackError

• eval.c (setup_exception): set backtrace in system stack error
  other than the pre-allocated sysstack_error. [Feature #6216]
• proc.c (Init_Proc): freeze the pre-allocated sysstack_error.
• vm_insnhelper.c (vm_stackoverflow): raise new instance for each
  times without calling any methods to keep the backtrace with no
  further stack overflow.