Re: [PATCH 1/4] Add sniffer for Cygwin x86_64 core dumps

Simon Marchi
2020-08-22T19:41:18Z

On 2020-08-21 12:28 p.m., Jon Turney wrote:
> On 21/08/2020 17:22, Simon Marchi wrote:
>> On 2020-08-21 11:25 a.m., Jon Turney wrote:
>>> The "dumper" currently shipping in x86_64 Cygwin is utterly broken. (See [1] et seq.).
>>>
>>> If you use "dumper" from the latest snapshot [2], you may have more success
>>>
>>> [1] https://cygwin.com/git/?p=newlib-cygwin.git;a=commitdiff;h=7dd1b08836e8a7bb37d330995096540afce152a0;hp=38f88601469f4a6ab7cf42e1f076775c99eb17f2
>>> [2] https://cygwin.com/snapshots/
>>
>> Ok, thanks for the tip. I'll give it a try with a snapshot.
>>
>> Do I just extract cygwin-20200821.tar.xz into my current Cygwin installation to overwrite
>> the corresponding files? If I want to revert to the stable versions, how can I do that?
>
> You should be able to just extract the dumper.exe from that archive, and
> use it. That's what I would suggest.

Hmm, just tried that, now running "dumper" does nothing:

Baube@DESKTOP-42816MD ~
$ dumper

Baube@DESKTOP-42816MD ~
$ echo $?
127

One thing that's weird is that in my installation, binaries are in C:\cygwin64\bin,
whereas in the snapshot, they are in usr/bin. Did the filesystem layout change
recently?

So I am not sure how to proceed to try the snapshot.

> If you were to extract it over an existing Cygwin installation, to
> revert you could use the cygwin setup program to re-install all cygwin*
> packages.

I successfully repaired my broken dumper by re-installing the cygwin* packages.

Simon