Cyg32 on Win64 fails with stack-protector

Corinna Vinschen
Mon Jun 25 09:44:00 GMT 2018

Yaakov, can you take a look, please?


On Jun 23 15:50, Ben RUBSON wrote:
> On 29 May 2018 18:59, Corinna Vinschen wrote:
> > I suggest to build your own Cygwin and bisect it.
> So I tried to bisect and had some difficulties.
> I used a fresh 32 bits installation on a 64 bits system and followed this
> howto :
> Prior to this commit : 6a848db44242a24d6570ef7994918c66ce483fd2
> 2017-11-29 - Yaakov Selkowitz - cygwin: export SSP functions
> (which is the one JonY suspects)
> With gcc 7.3, compilation fails with undefined __stack_chk_fail,
> __stack_chk_guard etc...
> With gcc 6.4, compilation succeeds. Cygwin correctly starts with the new
> cygwin1.dll, but then, some programs, such as cmake (cmake --help) do not
> show any output anymore.
> Same behavior using Cygwin snapshots. As it worked a few weeks ago, I tried
> to downgrade some runtime libraries, but with no luck.
> This is easily reproductible, just install Cygwin32 on a 64-bits system, and
> select Cygwin 2.9 library instead of the 2.10 one.
> So, unfortunately, I was not able to test any commit prior to the one given
> above.
> This commit however correctly compiles with both gcc 6.4 and 7.3.
> Cygwin correctly starts with it, program correctly show their output. And
> I'm able to reproduce the issue I opened this topic for.
> So something important has changed between 2017-11-14 and 2017-11-29 which
> triggers this bug.
> Perhaps the new SSP mechanism is more powerful than the previous one and
> triggers a long-time existing bug ?
> Thank you again,
> Ben

Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat
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