utils: Add 'version>=?'.

* guix/utils.scm (version>?): Clarify docstring.
  (version>=?): New procedure.

Merge branch 'core-updates'

Conflicts:
	gnu/packages/bootstrap.scm

gnu: Add toolchain support for 'armhf-linux'.

Based on preliminary work by John Darrington <john@darrington.wattle.id.au>.

* gnu/packages/cross-base.scm (xgcc-armhf): New variable.
* gnu/packages/gcc.scm (gcc-configure-flags-for-triplet): Add armhf case.
  (gcc-4.7)[pre-configure]: Add gcc/config/*/linux-eabi.h to the list
  of files in which to patch GLIBC_DYNAMIC_LINKER.
* gnu/packages/bootstrap.scm (glibc-dynamic-linker): Add armhf case.
* guix/utils.scm (gnu-triplet->nix-system, nix-system->gnu-triplet):
  Add armhf cases.

Move 'nix-system->gnu-triplet' to (guix utils) and export it.

* gnu/packages/commencement.scm (nix-system->gnu-triplet): Move to...
* guix/utils.scm (nix-system->gnu-triplet): ... here.  Fix docstring typo.

Merge branch 'master' into 'core-updates'.

guix: scripts: Add GUIX_BUILD_OPTIONS environment handling.

* doc/guix.texi (Invoking guix build): Mention 'GUIX_BUILD_OPTIONS'.
* guix/scripts/archive.scm: (append args (environment-build-options)).
* guix/scripts/build.scm: Ditto.
* guix/scripts/environment.scm: Ditto.
* guix/scripts/package.scm: Ditto.
* guix/scripts/system.scm: Ditto.
* guix/ui.scm (environment-build-options): New function.
* guix/utils.scm (arguments-from-environment-variable): New function.
* tests/guix-build.sh: Add tests.
* test-env.in: Unset GUIX_BUILD_OPTIONS.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add 'version-prefix' and 'version-major+minor'; use them.

The procedure version-prefix truncates a version string to a certain
number of components. version-major+minor is a special case of this,
which extracts the "major.minor" part of the string. Previously this
was handled by an expression common to several packages.

* guix/utils.scm (version-prefix, version-major+minor): New procedures
* gnu/packages/backup.scm (duplicity): Use version-major+minor.
* gnu/packages/cmake.scm (cmake): Likewise.
* gnu/packages/gnome.scm (libbonobo, libbonoboui): Likewise.
* gnu/packages/gnutls.scm (gnutls): Likewise.
* gnu/packages/mail.scm (gmime): Likewise.
* gnu/packages/mpd.scm (mpd): Likewise.
* gnu/packages/mpi.scm (openmpi): Likewise.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

utils: Micro-optimize 'bytevector->base16-string'.

This reduces run time of (package-derivation s emacs) by ~1.5%.

* guix/utils.scm (bytevector->base16-string): Traverse BV from the end
  so as to use 'string-concatenate' instead of
  'string-concatenate-reverse'.

utils: Add 'strip-keyword-arguments'.

* guix/utils.scm (strip-keyword-arguments): New procedure.
* tests/utils.scm ("strip-keyword-arguments"): New test.

utils: Create temporary files in $TMPDIR or /tmp.

Reported by Federico Beffa <beffa@ieee.org>.

* guix/utils.scm (call-with-temporary-output-file): Prepend $TMPDIR or
  /tmp to TEMPLATE.

Merge branch 'master' into core-updates

guix: utils: Add fold-tree and fold-tree-leaves.

* guix/utils.scm (fold-tree, fold-tree-leaves): New functions.
* tests/utils.scm: Add tests for them.

Merge branch 'master' into core-updates

Add (guix build syscalls).

* guix/build/syscalls.scm, tests/syscalls.scm: New files.
* Makefile.am (MODULES): Add guix/build/syscalls.scm.
  (SCM_TESTS): Add tests/syscalls.scm.
* guix/utils.scm (%libc-errno-pointer, errno): Remove; take from (guix
  build syscalls).

offload: '{send,receive}-files' wait for completion of the transfer.

Fixes situations where the remote 'guix build' is invoked before the
.drv has been completely copied, as reported at
<https://lists.gnu.org/archive/html/guix-devel/2014-04/msg00174.html>.

In some cases 'send-files' would return before the other end is done
importing the files, and so the subsequent 'guix build' invocation would
just miss the .drv file it refers to.

* guix/utils.scm (call-with-decompressed-port): Don't close PORT.
  (call-with-compressed-output-port): Likewise.
* tests/utils.scm ("compressed-output-port + decompressed-port"): Adjust
  accordingly.
* guix/scripts/offload.scm (send-files): Add explicit (close-pipe pipe)
  call.
  (retrieve-files): Likewise.

utils: Make 'errno' procedure more robust.

Partially fixes <http://bugs.gnu.org/17212>.

* guix/utils.scm (errno): Move definition of 'bv' outside of the
  procedure.  Use 'bytevector-s32-native-ref' or
  'bytevector-s64-native-ref' instead of 'bytevector-sint-ref'.

utils: Add 'call-with-decompressed-port' and 'call-with-compressed-output-port'.

* guix/utils.scm (call-with-decompressed-port,
  call-with-compressed-output-port): New procedures.
* tests/utils.scm ("compressed-output-port + decompressed-port"):
  Rewrite to use them.

utils: Add 'filtered-output-port' and 'compressed-output-port'.

* guix/utils.scm (filtered-output-port, compressed-output-port): New
  procedures.
* tests/utils.scm ("compressed-output-port + decompressed-port"): New
  test.

utils: Add 'decompressed-port' and 'compressed-port'.

* guix/utils.scm (decompressed-port, compressed-port): New procedures.
* guix/scripts/substitute-binary.scm (decompressed-port): Remove.
  (guix-substitute-binary): Pass a symbol or #f as the first argument to
  'decompress-port'.
* tests/utils.scm ("compressed-port, decompressed-port, non-file"): New
  test.

utils: 'filtered-port' doesn't leave dangling processes behind.

* guix/utils.scm (filtered-port): Make sure the 'execl' child process
  always exits, and does (primitive-_exit 1) upon execution failure.
  Use 'primitive-_exit' in the 'dump-port' child process.
* tests/utils.scm ("filtered-port, does not exist"): New test.