Alexandre,

Alexandre Hannud Abdo writes:
> /tmp/guix-build-[package].drv-1$ source environment-variables
> /tmp/guix-build-[package].drv-0/[package]$

If Guix used a different build directory depending on how many 
previous builds were kept, many builds would become 
irreproducible.

Instead, Guix always uses .drv-0 inside the build container.  When 
you pass --keep and the build fails and .drv-0 already exists on 
the host, it's renamed.

If you want ‘environment-variables’ to match the environment 
outside of the container, rename /tmp/guix-build-[package].drv-1 
to /tmp/guix-build-[package].drv-0.

Kind regards,

T G-R