[pkg-go] Please give back golang-1.8 (1.8.3-1) on s390x

[Anthony Fok]

On Sat, Jun 24, 2017 at 2:58 PM, Aurelien Jarno <aurelien at aurel32.net> wrote:
> On 2017-06-24 11:15, Anthony Fok wrote:
>> There seems to be a hiccup when golang-1.8 (1.8.3-1) was last built
>> for s390x on zemlinsky.
>>
>> Seeing the logs at
>>
>>     https://buildd.debian.org/status/logs.php?pkg=golang-1.8&arch=s390x
>>
>> It seems that zemlinsky fails consistently "Illegal Instruction" early
>> in the build,
>> while both zandonai and zani consistently succeed.
>>
>>     gb golang-1.8_1.8.3-1 . s390x
>
> Done.

Thank you so much, Aurelien!

>> Perhaps it is too much to ask, but would it be possible to set some
>> kind of automatic give-back whenever golang-1.8 (or future golang-1.9)
>> fails on zemlinsky?
>
> Automatic give back no, but we can blacklist the package on this build
> daemon. This is only a workaround for the problem below.

Even better!  Thank you!

>> Or, better yet, is there a way to find out what went wrong on
>> zemlinsky?  Is it an older machine with an older CPU that does not
>> support some newer CPU instructions?  (Sorry, I know nothing about
>> s390x and I am likely completely wrong.)
>
> That is actually the problem. On s390x golang requires a higher ISA than
> the one Debian targets. I have started to patch golang-1.7 to avoid these
> new instructions a few months ago, but upstream is not interested by
> supporting older CPUs and keep adding more usage of new instructions.

Thank you for your detailed explanation, and thank you for your
efforts in trying to solve it.

But yeah, I guess golang users on s390x would just have to accept the
fact that they need a newer CPU.  Thankfully, the majority of Debian's
s390x machines (buildd and porterbox), 3 out of 4, support the newer
instructions.  :-)

Cheers,
Anthony