Re: [PATCH v1 2/5] CI: drop Ubuntu 16.04

[Jan Beulich <jbeulich@xxxxxxxx>]

On 30.03.2026 18:17, Edwin Török wrote:
> Ubuntu 16.04 is EoL on 2026-04-02.

It going EOL very soon is a good reason; it causing ...

> It fails to build the emulator tests, probably due to a binutils that is too 
> old:
> 
> ```
> gcc -m32 -march=i686 -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall 
> -Wstrict-prototypes -Wno-unused-but-set-variable -Wno-unused-local-typedefs 
> -Werror -O2 -fomit-frame-pointer 
> -D__XEN_INTERFACE_VERSION__=__XEN_LATEST_INTERFACE_VERSION__ 
> -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -mno-tls-direct-seg-refs -fno-pie 
> -fno-exceptions -fno-asynchronous-unwind-tables -ffreestanding -nostdinc 
> -I/builds/xen-project/people/edwintorok/xen/tools/tests/x86_emulator/../../../tools/firmware/include
>  -fno-stack-protector -g0 -D_16 -mpclmul -mssse3 -mpclmul -ffixed-xmm0 -Os 
> -DVEC_SIZE=16 -c ssse3-pclmul.c
> /tmp/cchhD6n5.s: Assembler messages:
> /tmp/cchhD6n5.s:202: Error: junk at end of line, first unrecognized character 
> is `{'
> /tmp/cchhD6n5.s:203: Error: junk at end of line, first unrecognized character 
> is `{'
> /tmp/cchhD6n5.s:205: Error: junk at end of line, first unrecognized character 
> is `{'
> ```

... build issues in the test blobs isn't. The harness is specifically able to
cope with blob build failures. Another thing would be if test_x86_emulator.c
failed to build (but see below).

Is the above representative output anyway (i.e. is this not perhaps interleaved
output from a parallel build)? ssse3-pclmul.c, built with -mssse3 -mpclmul (i.e.
no AVX512 options), shouldn't really involve `{'. Furthermore we specifically
have a check in the Makefile, skipping building altogether when gcc and/or gas
are too old.

> Same test passes on Ubuntu 18.04.

Hard to believe that there wouldn't be at least some failures. Perhaps said
check prevents the attempt to build the harness there?

> Note: the minimum version of binutils might have to be updated.
> Ubuntu 16.04 had version 2.26.1, which satisfies the >= 2.25 requirement
> in the README, and yet it failed as shown above.

The harness is special, as said. Imo we shouldn't be updating the requirements
just for it. If anything, the mentioned gcc/gas check may need updating. {evex},
for example, requires gas 2.29 (i.e. gcc6 time frame). As does VPCMPESTRIQ. I
specifically have a local patch to make it possible to build the harness with
pre-gcc7 (I don't have any gcc6 anywhere, to that boundary may be off by 1). I
didn't think this hackery would be acceptable upstream.

Jan