Re: Turning off tests leads to a different store item

[Maxim Cournoyer]

Hi Felix,

Felix Lechner <felix.lechner@lease-up.com> writes:

> Hi,
>
> On Tue, Nov 07 2023, Maxim Cournoyer wrote:
>
>>> Felix Lechner via <help-guix@gnu.org> writes:
>>>
>>>> Those shortfalls are a consequence of our packaging habits. In an ideal
>>>> world, would running a test suite ever build a different derivation?
>>
>> You seem to be confusing 'derivation', which is the build recipe
>> description that a package "compiles" to, with the package output, the
>> result of executing the derivation.

[...]

> A source tree should produce the same derivation regardless of whether
> build-time tests ran or didn't. It should also pull the same substitute.

A source tree doesn't produce a derivation.  A derivation is the
complete build recipe that captures the source and the package
definition, that when built by the daemon produces a store item.

Earlier in the thread, I've mentioned that running a test suite can have
side effects such as happened in the past in Python with timestamps
being written to the loaded .pyc files when running test suites; we
can't ensure the test suite has no side-effects on the rest of the
package, so we can't simply assume building with #:tests? #f produces
the same as when building with #:tests? #t.

And to come back to the original idea: building with the tests run makes
sense for a distribution -- it's one of the rare things we have at our
disposal to ensure things are properly integrated and keep working.

-- 
Thanks,
Maxim