* tests/builders.scm, tests/derivations.scm, tests/packages.scm: Set
  #:use-substitutes? #f for %STORE.

* guix-package.in, tests/guix-package.sh: New files.
* configure.ac: Output `guix-package'.
* Makefile.am (TESTS): Add `tests/guix-package.sh'.
  (bin_SCRIPTS): Add `guix-package'.

* guix/store.scm (store-path-package-name): New procedure.
* tests/utils.scm ("store-path-package-name"): New test.

This was wrongfully committed in df1fab58.

* guix/utils.scm (hash-set-proc, hash-ref*, memoizing-lambda): Remove.

* tests/guix-build.sh: New file.
* Makefile.am (TESTS): Add it.
  (LOG_COMPILER): Rename to...
  (SCM_LOG_COMPILER): ... this.  Move flags to...
  (AM_SCM_LOG_FLAGS): ... this.
  (TEST_EXTENSIONS, SH_LOG_COMPILER, AM_SH_LOG_FLAGS): New variables.

* guix/ui.scm: New file.
* Makefile.am (MODULES): Add it.
* po/POTFILES.in: Add it.

* guix-build.in: Use it.
  (_, N_, leave): Remove.
  (guix-build): Use `with-error-handling' instead of the `guard' form.
* guix-download.in: Use it.
  (_, N_, leave): Remove.

* guix/build-system/gnu.scm (gnu-build): Add the `imported-modules'
  keyword parameter.  Pass it to `build-expression->derivation'.

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

* guix/store.scm (add-indirect-root): New operation.
* guix-build.in (show-help): Document `--root'.
  (%options): Add `--root'.
  (guix-build)[register-root]: New procedure.  Call it when `--root' is
  passed.

* guix/build/union.scm, tests/union.scm: New files.
* Makefile.am (MODULES): Add `guix/build/union.scm'.
  (TESTS): Add `tests/union.scm'.

* 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'.

* distro/packages/base.scm (bash): Set `#:parallel-build?' and
  `#:parallel-tests?' to #f.

* tests/builders.scm (%bootstrap-inputs): Use %BOOT0-INPUTS from the distro.
* tests/packages.scm (%bootstrap-inputs): Likewise.
* tests/derivations.scm (%coreutils): Alias for %BOOTSTRAP-COREUTILS&CO.

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

* Makefile.am (install-data-hook): New target.

* guix-build.in, guix-download.in: Define `prefix' and `datarootdir', so
  that `guilemoduledir' expands to something meaningful.

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

* Makefile.am (distro/packages/bootstrap/x86_64-linux/guile-bootstrap-2.0.6.tar.xz,
  distro/packages/bootstrap/i686-linux/guile-bootstrap-2.0.6.tar.xz):
  Make the target's parent directory.
* pre-inst-env.in (DISTRO_BOOTSTRAP_PATH): Add the builddir-relative
  directory.

* distro.scm (not-colon): New variable.
  (%patch-directory): Rename to...
  (%patch-path): ... this.  Turn into a list.  Expect $DISTRO_PATCH_PATH
  to be a colon-separated search path.
  (%bootstrap-binaries-directory): Rename to...
  (%bootstrap-binaries-path): ... this.  Likewise.
  (search-patch, search-bootstrap-binary): Adjust accordingly.

* pre-inst-env.in: Change to use `DISTRO_PATCH_PATH' and
  `DISTRO_BOOTSTRAP_PATH'.

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

* distro/patches: Move directory to...
* distro/packages/patches: ... here.
* Makefile.am (dist_patch_DATA): Adjust accordingly.
* pre-inst-env.in (DISTRO_PATCH_DIRECTORY): Likewise.

* Makefile.am (.scm.go): Use `pre-inst-env' instead of re-defining the
  environment variables, except for `DISTRO_INSTALLED_PATCH_DIRECTORY'
  and `DISTRO_INSTALLED_BOOTSTRAP_DIRECTORY'.

* guix/packages.scm: Export `package-error?' and `package-input-error?'.
* guix-build.in (guix-build): Catch `&package-input-error' conditions,
  print a human-readable message, and exit.

* guix/utils.scm (source-properties->location): Use COL + 1.

* distro/packages/bootstrap/i686-linux/bash,
  distro/packages/bootstrap/i686-linux/mkdir,
  distro/packages/bootstrap/i686-linux/tar,
  distro/packages/bootstrap/i686-linux/xz: New files.

* distro/packages/base.scm (%bootstrap-coreutils&co,
  %bootstrap-binutils, %bootstrap-glibc, %bootstrap-gcc): Add hashes of
  the i686-linux tarballs.

* Makefile.am (bootstrap_i686_linuxdir, dist_bootstrap_i686_linux_DATA,
  nodist_bootstrap_i686_linux_DATA): New variables
  (DISTCLEANFILES): Add $(nodist_bootstrap_i686_linux_DATA).
  (distro/packages/bootstrap/i686-linux/guile-bootstrap-2.0.6.tar.xz):
  New rule.

* distro/packages/base.scm (gcc-4.7)[arguments]: In the `pre-configure'
  phase, patch all the relevant gcc/config files, not just those for
  x86_64-linux-gnu.

* guix/build/utils.scm (substitute*): Remove special syntax for
  list-of-files; instead, check whether FILE is `list?' at run time.

* distro/packages/base.scm (gcc-4.7, %binutils-static): Adjust
  accordingly.

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

* guix/utils.scm (nixpkgs-derivation): Add a `system' parameter.  Pass
  it in the `nix-instantiate' invocation.

* guix/packages.scm (package-source-derivation): Add `system'
  parameter.  Pass it to METHOD.
  (package-derivation)[expand-input]: Pass SYSTEM to
  `package-derivation' and `package-source-derivation'.

* distro/packages/base.scm (package-with-bootstrap-guile)[boot]: Pass
  SYSTEM to FETCH.

* guix/derivations.scm (imported-files): Call
  `build-expression->derivation' with SYSTEM, not (%current-system).
  (build-expression->derivation): Pass SYSTEM to `imported-modules' and
  `compiled-modules'.

* guix/derivations.scm (%guile-for-build): Initialize to #f.
  (imported-files, imported-modules, compiled-modules): Add `guile'
  keyword parameter.  Pass it down to `build-expression->derivation'.
  (build-expression->derivation)[guile-drv]: New variable.  Pass it as
  the #:guile parameter for `imported-modules' and `compiled-modules'.

* tests/derivations.scm: Set %GUILE-FOR-BUILD to the derivation of
  %BOOTSTRAP-GUILE.

* distro/packages/base.scm (%boot4-inputs): New variable.
  (guile-final): Use it.
  (%final-inputs): Build with %BOOT4-INPUTS, not %BOOT3-INPUTS.

* distro/packages/base.scm (ncurses): Pass #:patch-shebangs? #f.

* distro/packages/base.scm (%bootstrap-inputs): Switch to using our own
  bootstrap binaries instead of those from Nixpkgs.

* distro/packages/base.scm (glibc-final): Pass `--enable-obsolete-rpc'.
  (%bootstrap-glibc): Update hash accordingly.

* distro/packages/base.scm (%glibc-stripped): Copy all of Linux-Libre's
  `include/asm' directory; copy a few linux/ headers too.
  (%bootstrap-glibc): Update tarball hash.

* distro/packages/base.scm (%bootstrap-gcc): New variable.

* guix-download.in: New file.
* configure.ac: Emit `guix-download' and make it executable.
* Makefile.am (bin_SCRIPTS): Add `guix-download'.
* po/POTFILES.in: Add `guix-download.in'.

* guix/store.scm (write-arg, read-arg): Add `base16' literal and
  corresponding rule.
  (query-path-hash): New operation.

* tests/derivations.scm ("fixed-output derivation"): Check whether
  `query-path-hash' returns a bytevector.