On Wed, Jul 03, 2024 at 11:03:09AM -0400, Boyuan Yang wrote:
> X-Debbugs-CC: t...@invisible-island.net
>
> 在 2024-07-03星期三的 16:28 +0200，Kristian Nielsen写道：
> > Package: mawk
> > Version: 1.3.4.20240622-1
> > Severity: normal
> >
> > Dear Maintainer,
> >
> > Running mawk produces wrong output from rand() on i386:
> >
> > $ echo | mawk 'BEGIN {srand(10);} {print rand()};'
> > 0.158578
> > $ echo | mawk 'BEGIN {srand(10);} {print rand()};'
> > -0.276944
> > $ echo | mawk 'BEGIN {srand(10);} {print rand()};'
> > -0.387807
> > $ echo | mawk 'BEGIN {srand(10);} {print rand()};'
> > 0.470306
> >
> > The result of rand() should never be negative; and it should be
> > deterministic after calling srand().
> >
> > This occurs on i386 (tested in sbuild --arch=i386 as part of debugging a
> > reproducible build problem of package openscad).
> >
> > The expected output is the same value between 0 and 1, for example:
> >
> > $ echo | mawk 'BEGIN {srand(10);} {print rand()};'
> > 0.559536
> > $ echo | mawk 'BEGIN {srand(10);} {print rand()};'
> > 0.559536
> > $ echo | mawk 'BEGIN {srand(10);} {print rand()};'
> > 0.559536
> >
> > The longer story, for completeness: I am the maintainer for openscad, and I
> > see openscad sometimes failing to build reproducibly on (only) i386 during
> > the past year. The root cause seems to be a test script that calls awk and
> > behaves unexpectedly due to getting a negative number out of rand().
> >
> > The problem does not seem to occur on amd64 or arm64. Openscad doesn't build
> > on armhf, so not sure if the problem in mawk is specific to i386 or may be
> > specific to 32-bit for example.
>
> Ack. Reproducible on Debian Sid (mawk/1.3.4.20240622), not reproducible on
> Debian 12
> Bookworm (mawk/1.3.4.20200120). Likely a regression since 2020.odd - I can reproduce the problem, but what I'm seeing is older. I'll investigate further. -- Thomas E. Dickey <dic...@invisible-island.net> https://invisible-island.net
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