bug#28310: guix build -n misses package builds

bug#28310: guix build -n misses package builds

[Andreas Enge]

Hello,

I am right now in the process of updating pari-gp to version 2.9.3.
After building it on a git check-out of three days ago, which went smoothly,
I rebased my patch on today's master and was pleased to see that no rebuild
was needed:

$ ./pre-inst-env guix build pari-gp -n
outputs nothing.

However, once the -n dropped, the gd package gets built.
And then it is starting ruby, which has no connection to pari-gp:
Downloading https://mirror.hydra.gnu.org/guix/nar/229n3pzp5bdmbdvwslg0dxliysas92k5-ruby-2.4.1.tar.xz...
   ruby-2.4.1.tar.xz  9.5MiB                                                                                                       22KiB/s 00:06 [                    ]   1.3%^

Andreas

bug#28310: guix build -n misses package builds

[Ludovic Courtès]

Hello,

Andreas Enge <andreas@enge.fr> skribis:

> I am right now in the process of updating pari-gp to version 2.9.3.
> After building it on a git check-out of three days ago, which went smoothly,
> I rebased my patch on today's master and was pleased to see that no rebuild
> was needed:
>
> $ ./pre-inst-env guix build pari-gp -n
> outputs nothing.
>
> However, once the -n dropped, the gd package gets built.
> And then it is starting ruby, which has no connection to pari-gp:
> Downloading https://mirror.hydra.gnu.org/guix/nar/229n3pzp5bdmbdvwslg0dxliysas92k5-ruby-2.4.1.tar.xz...
>    ruby-2.4.1.tar.xz  9.5MiB                                                                                                       22KiB/s 00:06 [                    ]   1.3%^

“-n” now implies “--no-grafts” (commit
fd59105c49965db956fac73c68d8b00d068f5d5c).  This was motivated by the
need to have -n really perform a dry run.

The downside is that with -n we now see only half of the build plan, and
when we remove -n, we start with the other half of the build plan,
grafting.

The “build continuation” idea of ‘wip-gexp-grafts’, discussed in
<https://bugs.gnu.org/22990>, could in theory help with that.

Ludo’.

bug#28310: guix build -n misses package builds

[Andreas Enge]

Hello,

On Sat, Sep 02, 2017 at 01:08:12AM +0200, Ludovic Courtès wrote:
> “-n” now implies “--no-grafts” (commit
> fd59105c49965db956fac73c68d8b00d068f5d5c).  This was motivated by the
> need to have -n really perform a dry run.

if I understand your answer correctly, then no output with "-n" means that
the ungrafted packages are already available in my store.

> The downside is that with -n we now see only half of the build plan, and
> when we remove -n, we start with the other half of the build plan,
> grafting.

Then this other half would just be grafting, which would not require to
download source and build packages locally.

Or are the built packages the replacements for packages with security
updates, that are grafted upon the existing packages?

Andreas

bug#28310: guix build -n misses package builds

[Ludovic Courtès]

Hi,

Andreas Enge <andreas@enge.fr> skribis:

> On Sat, Sep 02, 2017 at 01:08:12AM +0200, Ludovic Courtès wrote:
>> “-n” now implies “--no-grafts” (commit
>> fd59105c49965db956fac73c68d8b00d068f5d5c).  This was motivated by the
>> need to have -n really perform a dry run.
>
> if I understand your answer correctly, then no output with "-n" means that
> the ungrafted packages are already available in my store.

Exactly.

>> The downside is that with -n we now see only half of the build plan, and
>> when we remove -n, we start with the other half of the build plan,
>> grafting.
>
> Then this other half would just be grafting, which would not require to
> download source and build packages locally.

Grafting usually means downloading/building the replacements first, and
finally performing the actual graft.

I agree it makes it harder to follow from a user viewpoint.

Cheers,
Ludo’.

bug#28310: guix build -n misses package builds

[Andreas Enge]

On Sat, Sep 02, 2017 at 01:08:12AM +0200, Ludovic Courtès wrote:
> “-n” now implies “--no-grafts” (commit
> fd59105c49965db956fac73c68d8b00d068f5d5c).  This was motivated by the
> need to have -n really perform a dry run.
> 
> The downside is that with -n we now see only half of the build plan, and
> when we remove -n, we start with the other half of the build plan,
> grafting.
> 
> The “build continuation” idea of ‘wip-gexp-grafts’, discussed in
> <https://bugs.gnu.org/22990>, could in theory help with that.

Okay, so to simplify, I am closing this bug report.

Andreas

bug#28310: guix build -n misses package builds

[Ludovic Courtès]

Andreas Enge <andreas@enge.fr> skribis:

> On Sat, Sep 02, 2017 at 01:08:12AM +0200, Ludovic Courtès wrote:
>> “-n” now implies “--no-grafts” (commit
>> fd59105c49965db956fac73c68d8b00d068f5d5c).  This was motivated by the
>> need to have -n really perform a dry run.
>> 
>> The downside is that with -n we now see only half of the build plan, and
>> when we remove -n, we start with the other half of the build plan,
>> grafting.
>> 
>> The “build continuation” idea of ‘wip-gexp-grafts’, discussed in
>> <https://bugs.gnu.org/22990>, could in theory help with that.
>
> Okay, so to simplify, I am closing this bug report.

I’ve reopened it (it’s a real problem after all) so we can keep track of
it, and feel the relief when we finally close it.  :-)

Ludo’.

bug#28310: guix build -n misses package builds

[Ludovic Courtès]

Hello,

ludo@gnu.org (Ludovic Courtès) skribis:

> Andreas Enge <andreas@enge.fr> skribis:
>
>> I am right now in the process of updating pari-gp to version 2.9.3.
>> After building it on a git check-out of three days ago, which went smoothly,
>> I rebased my patch on today's master and was pleased to see that no rebuild
>> was needed:
>>
>> $ ./pre-inst-env guix build pari-gp -n
>> outputs nothing.
>>
>> However, once the -n dropped, the gd package gets built.
>> And then it is starting ruby, which has no connection to pari-gp:
>> Downloading https://mirror.hydra.gnu.org/guix/nar/229n3pzp5bdmbdvwslg0dxliysas92k5-ruby-2.4.1.tar.xz...
>>    ruby-2.4.1.tar.xz  9.5MiB                                                                                                       22KiB/s 00:06 [                    ]   1.3%^
>
> “-n” now implies “--no-grafts” (commit
> fd59105c49965db956fac73c68d8b00d068f5d5c).  This was motivated by the
> need to have -n really perform a dry run.
>
> The downside is that with -n we now see only half of the build plan, and
> when we remove -n, we start with the other half of the build plan,
> grafting.

This is now fixed with this patch series:

  https://issues.guix.gnu.org/issue/40130

It does mean that “The following derivations will be built” can be
printed several times during a build.  That’s a natural consequence of
having dynamic dependencies (grafts) in the graph: we can’t always
statically determine what’s going to be built.

> The “build continuation” idea of ‘wip-gexp-grafts’, discussed in
> <https://bugs.gnu.org/22990>, could in theory help with that.

‘with-build-handler’ also has to do with continuations, only in a
different way.  :-)

Ludo’.