bug#41669: Cross-compiled powerpc64-linux bootstrap-tarballs not reproducible

[Ludovic Courtès]

Hi Chris & all,

Apologies for taking so long to reply!  Pinging me on IRC was the right
move.  :-)

Chris Marusich <cmmarusich@gmail.com> skribis:

> I'm afraid I've hit a snag using what you've uploaded, though.  It looks
> like we'll need to extract bash, mkdir, tar, and xz from
> static-binaries-0-powerpc64le-linux-gnu.tar.xz and place a copy of each
> in the following locations:
>
> - https://alpha.gnu.org/gnu/guix/bootstrap/powerpc64le-linux/20210106/bash
> - https://alpha.gnu.org/gnu/guix/bootstrap/powerpc64le-linux/20210106/mkdir
> - https://alpha.gnu.org/gnu/guix/bootstrap/powerpc64le-linux/20210106/tar
> - https://alpha.gnu.org/gnu/guix/bootstrap/powerpc64le-linux/20210106/xz
>
> Could you do that?  The reason why it's necessary is described below.

I’ve uploaded these four files now.

> I've started making changes locally to (gnu packages bootstrap).  So
> far, with the attached patch, I'm able to do the following things on my
> POWER9 machine running ppc64le Debian (unstable).
>
> I can successfully build Guix from source using Debian packages (and a
> manually-built copy of guile-avahi and guile-gnutls).  With my patch, I
> still have to supply the "--with-courage" configure option.  Although
> "make" succeeded, "make check" failed on the following tests:
>
> - tests/build-utils.scm
> - test/challenge.scm
> - tests/containers.scm
> - tests/debug-link.scm
>
> The failures fell into two categories:
>
> - Some tests couldn't download the bootstrap bash.
> - In tests/containers.scm, call-with-container evaluated to #f when it
>   wasn't supposed to.

Perhaps we can investigate them later.

> Nevertheless, I created the necessary build users and started the
> guix-daemon via pre-inst-env.  I then tried building a simple package:
>
>   ./pre-inst-env guix build -e '(@@ (gnu packages bootstrap) 
> %bootstrap-coreutils&co)'

[...]

> Starting download of 
> /gnu/store/2phdifnfw6i989rqbav04zakxx7qb165-static-binaries-0-powerpc64le-linux-gnu.tar.xz
> From 
> https://ftp.gnu.org/gnu/guix/bootstrap/powerpc64le-linux/20210106/static-binaries-0-powerpc64le-linux-gnu.tar.xz...

> failed to download "/gnu/store/0kaj6l1ccw0qd0289hii7qhr828s71sv-bash" from 
> ("https://git.savannah.gnu.org/cgit/guix.git/plain/gnu/packages/bootstrap/powerpc64le-linux/20210106/bash";
>  "http://lilypond.org/janneke/guix/powerpc64le-linux/20210106/bash";)
> builder for `/gnu/store/ix4mpvzxfi1hrmvdmmpgqhm9x1cdh347-bash.drv' failed to 
> produce output path `/gnu/store/0kaj6l1ccw0qd0289hii7qhr828s71sv-bash'

Note that for testing purposes, you could always work around this by
adding these four files to the store with the ‘add-to-store’ RPC (I
don’t think ‘guix download’ would work because you need the executable
bit.)

> By the way, I've noticed that the other architectures don't seem to have
> "raw" binaries at all on alpha.gnu.org.  Maybe you already knew this,
> but it seems that the "raw" binaries are actually downloaded from this
> specific URL (see the bootstrap-executable-file-name procedure):
>
> https://git.savannah.gnu.org/cgit/guix.git/plain/gnu/packages/bootstrap/?id=44f07d1dc6806e97c4e9ee3e6be883cc59dc666e
>
> Is that intended?

Yes: these files used to be in version control, part of the Guix source
tarball, but now we just download them (commit
836a85da0e8609d40716581be00802ee43463038).

> I was surprised to discover that we store these four "raw" binaries in
> a totally separate place.  That seems like it would make it easy for
> someone to accidentally forget to update the "raw" binaries when they
> update an architecture's bootstrap tarballs.

They’re visible in the dependency graph though, and they don’t need to
ever change.

Ludo’.