Re: Desktops on non-x86_64 systems

[Maxim Cournoyer]

Hello,

Ricardo Wurmus <rekado@elephly.net> writes:

> Ludovic Courtès <ludo@gnu.org> writes:
>
>> We could try that, but IMO we first need a solution within days—we
>> just
>> cannot reasonably let this branch go on for longer than that. The
>> librsvg 2.40 hack would give us Xfce (maybe GNOME?) on i686 today.
>>
>> Perhaps we can address all this in several steps:
>>
>>   1. apply the librsvg 2.40 hack now so we can merge
>>      ‘core-updates-frozen’ this week for real;
>>
>>   2. later on, introduce some Rust binary for non-x86_64; that
>> would
>>      lead to rebuilds only on those architectures;
>>
>>   3. eventually, update mrustc (and have it call gcc with -O0 to
>> reduce
>>      its memory footprint), or use GCC-Rust instead of that’s
>> viable.
>>
>> WDYT?
>
> This sounds sensible.  Merging core-updates-frozen does *not* mean
> that it needs to be ready for release.  It’s been delayed for too 
> long and further delays just serve to taint our morale and drain our
> energy, applying fixes again and again with no end in sight.
>
> These ongoing delays have made core-updates-frozen grow so much in
> scope that we cannot afford to delay a merge any longer.  Let’s 
> merge asap, even if that means using an older librsvg right now. Then
> add rust for non-x86_64 — either by cross-building it ourselves or
> getting an existing binary to restore feature parity. Then work on a
> long-term solution.

I hear your frustration w.r.t to delays; I don't mind if this stopgap
solution is implemented *now*, but I'm skeptical that it'd allow GNOME
to built.

I've been experimenting with a cross-compiled rustc; it's building, but
there are some things to fix (the ld-wrapper used to wrap rustc so far
is the native one, which is incorrect I believe, and cargo doesn't find
the correct libz, libssh2).

The branch is wip-cross-built-rust on our Savannah repo.

I 'guix pack'd rust-i686-linux and tried it on a 32-bit Debian VM:

For rustc:

--8<---------------cut here---------------start------------->8---
$ file /gnu/store/6fkn8fc0m642xlnbblv3026cpp4i2411-profile/bin/rustc
/gnu/store/6fkn8fc0m642xlnbblv3026cpp4i2411-profile/bin/rustc: symbolic link to 
/gnu/store/50fsf4g5xb51qa9jg7xhaaxcwh7h5v2w-rust-i686-linux-1.54.0/bin/rustc

 $ file 
/gnu/store/50fsf4g5xb51qa9jg7xhaaxcwh7h5v2w-rust-i686-linux-1.54.0/bin/.rustc-real
/gnu/store/50fsf4g5xb51qa9jg7xhaaxcwh7h5v2w-rust-i686-linux-1.54.0/bin/.rustc-real:
ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically
linked, interpreter
/gnu/store/miwzifnpn3lgzd6kvkcmz1i0hx7vvdfm-glibc-cross-i686-linux-gnu-2.33/lib/ld-linux.so.2,
for GNU/Linux 2.6.32, stripped

$ /gnu/store/6fkn8fc0m642xlnbblv3026cpp4i2411-profile/bin/rustc --version
rustc 1.54.0
--8<---------------cut here---------------end--------------->8---

For cargo:

--8<---------------cut here---------------start------------->8---
$ file /gnu/store/6fkn8fc0m642xlnbblv3026cpp4i2411-profile/bin/cargo
/gnu/store/6fkn8fc0m642xlnbblv3026cpp4i2411-profile/bin/cargo: symbolic link to 
/gnu/store/vhfdxbxla54n56qggv975c39vyaa0z91-rust-i686-linux-1.54.0-cargo/bin/cargo

$ file 
/gnu/store/vhfdxbxla54n56qggv975c39vyaa0z91-rust-i686-linux-1.54.0-cargo/bin/cargo
/gnu/store/vhfdxbxla54n56qggv975c39vyaa0z91-rust-i686-linux-1.54.0-cargo/bin/cargo:
 ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically 
linked, interpreter 
/gnu/store/miwzifnpn3lgzd6kvkcmz1i0hx7vvdfm-glibc-cross-i686-linux-gnu-2.33/lib/ld-linux.so.2,
 for GNU/Linux 2.6.32, stripped

$ 
/gnu/store/vhfdxbxla54n56qggv975c39vyaa0z91-rust-i686-linux-1.54.0-cargo/bin/cargo
 --version
/gnu/store/vhfdxbxla54n56qggv975c39vyaa0z91-rust-i686-linux-1.54.0-cargo/bin/cargo:
error while loading shared libraries: libz.so: wrong ELF class:
ELFCLASS64

$ ldd 
/gnu/store/vhfdxbxla54n56qggv975c39vyaa0z91-rust-i686-linux-1.54.0-cargo/bin/cargo
 
        linux-gate.so.1 (0xb7f22000)
        libz.so => not found
        libcurl.so.4 => not found
        libssl.so.1.1 => /lib/i386-linux-gnu/libssl.so.1.1 (0xb71ae000)
        libcrypto.so.1.1 => /lib/i386-linux-gnu/libcrypto.so.1.1 (0xb6eeb000)
        libgcc_s.so.1 => 
/gnu/store/x5y2ngh1asiv3dkcbzaga9ml56xcm3ps-gcc-cross-i686-linux-gnu-10.3.0-lib/lib/gcc/i686-linux-gnu/10.3.0/../../../../i686-linux-gnu/lib/libgcc_s.so.1
 (0xb6ecb000)
        libpthread.so.0 => 
/gnu/store/miwzifnpn3lgzd6kvkcmz1i0hx7vvdfm-glibc-cross-i686-linux-gnu-2.33/lib/libpthread.so.0
 (0xb6eaa000)
        libm.so.6 => 
/gnu/store/miwzifnpn3lgzd6kvkcmz1i0hx7vvdfm-glibc-cross-i686-linux-gnu-2.33/lib/libm.so.6
 (0xb6da8000)
        libdl.so.2 => 
/gnu/store/miwzifnpn3lgzd6kvkcmz1i0hx7vvdfm-glibc-cross-i686-linux-gnu-2.33/lib/libdl.so.2
 (0xb6da0000)
        libc.so.6 => 
/gnu/store/miwzifnpn3lgzd6kvkcmz1i0hx7vvdfm-glibc-cross-i686-linux-gnu-2.33/lib/libc.so.6
 (0xb6bb0000)
        
/gnu/store/miwzifnpn3lgzd6kvkcmz1i0hx7vvdfm-glibc-cross-i686-linux-gnu-2.33/lib/ld-linux.so.2
 => /lib/ld-linux.so.2 (0xb7f24000)
--8<---------------cut here---------------end--------------->8---

To be continued...

Maxim