Until now 'compiled-modules' would override (guix build utils) with its
own. Thus, when asked to build a different (guix build utils),
via #:module-path, it would fail badly because a (guix build utils)
module was already loaded and possibly incompatible with the new one.
This happened when running 'guix pull --branch=core-updates' from
current master: in 'core-updates', (guix build utils) exports
'ignore-error?' but in 'master' it does not. Thus, 'guix pull' would
fail with:
no binding `invoke-error?' in module (guix build utils)
builder for `/gnu/store/…-module-import-compiled.drv' failed with exit code 1
cannot build derivation `/gnu/store/…-compute-guix-derivation.drv': 1 dependencies couldn't be built
This patch fixes it.
* guix/gexp.scm (compiled-modules)[build-utils-hack?]: New variable.
[build]: Load MODULES/build/utils.scm when it exists.
5d669883ec