[Pkg-rust-maintainers] Bug#851150: Bug#851150: src:rustc: FTBFS on s390x due to Illegal instruction

[Emilio Pozuelo Monfort]

On Sun, 26 Feb 2017 18:56:00 +0000 Ximin Luo <infinity0 at debian.org> wrote:
> Ximin Luo:
> > Ximin Luo:
> >>> [..]
> >>
> >> 1.15.1 succeeded for me just now on zelenka.debian.org the s390x porterbox, however there was a test failure.
> >>
> >> I'll retry 1.14.0 on zelenka again and see if it fails. If it does, then I'll assume the issue was fixed in 1.15.1 and try uploading that to the buildds (after fixing the test failure). If it doesn't fail, then it could be due to a CPU difference between zelenka and zemlinsky.
> >>
> > 
> > Looks like the test failure was #842634; the zelenka schroot has two entries for "127.0.0.1 localhost". Unfortunately I can't write to that file so I'll just assume the build "would have worked".
> > 
> > OTOH the 1.14 build I started has also got past stage0 libcore - where zemlinsky failed in my OP. So probably the failure is due to a CPU difference between zemlinsky (z10) and zelenka (z13).
> > 
> > https://db.debian.org/machines.cgi?host=zemlinsky
> > https://db.debian.org/machines.cgi?host=zelenka
> > 
> > Actually this is not a surprise given that it also succeded on z13 Ubuntu; I should probably have looked at these pages before doing these >.<
> > 
> 
> Hi Debian s390 list, could someone please take a look at this? Details of the OP are here:
> 
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=851150
> 
> The TL;DR is that rust 1.14 and 1.15 both compile fine on a z13 but fail on z10. I don't have any access to any other z-machines apart from zelenka (z13).
> 
> What is slightly weird, is that rust claims that LLVM supports z10:
> 
> https://github.com/rust-lang/rust/blame/master/src/librustc_back/target/s390x_unknown_linux_gnu.rs
> 
> But I don't have access to an actual z10 to be able to use gdb to figure out what the actual Illegal instruction is.
> 
> There is a wider issue here however. I see that #844258 for golang resulted it in being removed for s390x. The reason was that Go no longer supports z10, but only z196 and onwards.
> 
> However, perhaps it's time for the Debian s390 team to consider bumping the requirements for s390x in Debian? Now we have (potentially) two programming languages who don't support z10, and whilst support might be in theory be addable/maintainable, it appears nobody is stepping up to do this work. Also Ubuntu's baseline is already z13.

The s390x baseline has been raised:

https://lists.debian.org/debian-s390/2018/02/msg00008.html

So I guess it's time to try to bootstrap rust on s390x once again.

Cheers,
Emilio