* release.nix: Revert to commit 4050e5d6.

* release.nix (unchrootedNixpkgs): New function.
  (jobs)[tarball, build, build_disable_daemon, distro): Use it.
  Should fix <http://hydra.gnu.org:3000/build/7279>.

* release.nix: s/buildNativeInputs/nativeBuildInputs/.

* release.nix (tarball): Use a minimal Git.

* release.nix (unchroot): Operate recursively on build inputs.

* release.nix (unchroot): New function.
  (jobs)[tarball, build, build_disable_daemon]: Use it.

Change all license headers, except guix/build/* and ld-wrapper.scm, with
this code:

  (use-modules (guix build utils)
	       (srfi srfi-1))

  (fluid-set! %default-port-encoding "UTF-8")

  (substitute* (remove (lambda (f)
			 (or (string-contains f ".tar.")
			     (string-contains f ".git/")
			     (string-contains f ".so")
			     (string-suffix? ".o" f)
			     (string-suffix? ".a" f)
			     (string-suffix? ".go" f)
			     (string-suffix? ".pdf" f)
			     (string-suffix? ".png" f)
			     (string-suffix? ".info" f)
			     (equal? (basename f) "guix-daemon")
			     (equal? (basename f) "nix-setuid-helper")
			     (string-contains f "nix-upstream/")
			     (string-contains f "distro/packages/bootstrap/")))
		       (find-files "." "\\.[a-z]+$"))
    (("^([[:graph:]]+) This file is part of Guix." _ comment-start)
     (string-append comment-start " This file is part of GNU Guix."))
    (("^([[:graph:]]+) Guix --- Nix package management.*" _ comment-start)
     (string-append comment-start
		    " GNU Guix --- Functional package management for GNU\n"))
    (("^([[:graph:]]+) Guix is " _ comment-start)
     (string-append comment-start " GNU Guix is "))
    (("^([[:graph:]]+) along with Guix." _ comment-start)
     (string-append comment-start " along with GNU Guix."))
    (("^([[:graph:]]+) Copyright \\(C\\)" _ comment-start)
     (string-append comment-start " Copyright ©")))

Change headers using C-style comments manually.

* release.nix (bootstrap_guile): Update URLs and SHA256.
  (build)[preBuild]: Adjust tarball name.

* release.nix (tarball, build): Use /nix/var as localstatedir, as a
  follow-up to 7f4f0651.

* release.nix (tarball): Replace "gnulib" by "nix".

* release.nix (tarball): Replace "gnulib" by "nix".

* release.nix (build_disable_daemon): New job.

* release.nix (build): Remove `__noChroot' and `preConfigure'.

* release.nix (tarball): Add `preAutoconf'.  Augment `buildInputs' and
  `configureFlags' to allow daemon builds.
  (build): Likewise.

* release.nix (jobs.tarball)[configureFlags]: Pass
  `--with-libgcrypt-prefix'.

* configure.ac: Always show the result of checking for Nixpkgs.  Don't
  warn when Nixpkgs is not found.
* Makefile.am (AM_DISTCHECK_CONFIGURE_FLAGS): Remove `--with-nixpkgs'
  flag.
* guix/utils.scm (%nixpkgs-directory): Use either the compile-time or
  the run-time `NIXPKGS' environment variable.
* release.nix (jobs.tarball, jobs.build): Remove `--with-nixpkgs'
  configure flag.
* README: Mark Nixpkgs as optional.

* distro/packages/databases.scm, distro/packages/guile.scm,
  distro/packages/typesetting.scm: Change uses of `nixpkgs-derivation*'
  to `nixpkgs-derivation', to avoid failing at compile-time.

* release.nix (distro.hello): Use `guix-build --no-substitutes', to
  avoid failures due to unavailable stale substitutes on
  hydra.nixos.org.

* release.nix (distro.hello)[buildPhase]: Tee the log to $out.  Add a
  `name' attribute; remove `buildInputs' and instead use the full path
  to `guix-build'.

* release.nix (distro.hello): New job.

* release.nix (bootstrap_guile): New variable.
  (build)[preBuild]: New attribute.

* release.nix: Define `succeedOnFailure', `keepBuildDirectory', and
  `buildOutOfSourceTree'.
  (build): Inherit them.

* release.nix (tarball)[buildNativeInputs]: Add `texinfo'.

* release.nix (build)[configureFlags]: Add `--with-libgcrypt-prefix'.

* release.nix: Add `preConfigure' and `__noChroot' attributes.

* release.nix: New file.
* Makefile.am (EXTRA_DIST): Add it.