* gnu/packages/commencement.scm (%bootstrap-guile+guild): Make public.
[properties]: New field.
* gnu/system/bootstrap.scm (hash-script): New procedure.
(bootstrapping-os): Wrap OBJ in 'hash-script'.

DRAFT: We should probably just use 'let-values' instead.

* guix/serialization.scm (define-values) [not guile-2.2]: New macro.

* gnu/packages/commencement.scm (%bootstrap-guile+guild): New variable.

This allows us to perform arbitrary builds on a system that has no
userland besides the build process itself, running as PID 1.

Suggested by Vagrant Cascadian.

DRAFT: The resulting system does build things, but this is all happening
into memory, which may or may not be a problem (it allows us to not have
disk drivers in the kernel!).  More importantly, it does not display
anything upon completion, and the build result is lost as well.

* gnu/system/bootstrap.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.

DRAFT: Add tests.

* guix/gexp.scm (<object-sources>): New record type.
(object-sources-compiler): New gexp compiler.

DRAFT: Add tests.

* guix/gexp.scm (<raw-derivation-closure>): New record type.
(sorted-references): New procedure.
(raw-derivation-closure-compiler): New gexp compiler.

* guix/derivations.scm (derivation-input-fold): Add #:skip-dependencies?.

* guix/store.scm (topologically-sorted): Add #:cut? and honor it.
* tests/store.scm ("topologically-sorted, one item, cutting"): New
test.

This allows (guix monads) to be compiled and use on the current
"guile-bootstrap" package, which is Guile 2.0.9.

* guix/monads.scm (define-syntax-parameter-once): Add 'cond-expand' form.

* guix/utils.scm (version-compare): Delay 'strverscmp' and force it when
called.