build: Fix typo that would lead to hitting the socket name length limit.

* tests/guix-register.sh: Remove redundant $new_store in $NIX_STATE_DIR,
  introduced in 689142cd ("guix-register: Add '--state-directory'
  parameter.")  Reported by Eric Bavier <ericbavier@gmail.com> and
  Alen Skondro <askondro@gmail.com>.

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.

guix-register: Add '--state-directory' parameter.

* nix/guix-register/guix-register.cc (GUIX_OPT_STATE_DIRECTORY): New
  macro.
  (parse_opt): Honor it.
* tests/guix-register.sh: Add test with '--state-directory'.
* guix/store.scm (register-path): Add #:state-directory parameter.

records: Report unknown field names in inheriting forms.

* guix/records.scm (define-record-type*)[record-inheritance]: Check for
  unexpected field names.
* tests/records.scm ("define-record-type* with let* behavior"): Return
  #t, not *unspecified*.
  ("define-record-type* & inherit & extra initializers"): New test.

records: Add tests for error cases.

* tests/records.scm (test-module): New procedure.
  ("define-record-type* & missing initializers",
  "define-record-type* & extra initializers"): New tests.

gexp: Gracefully handle printing of gexps with spliced references.

* guix/gexp.scm (write-gexp): Wrap 'write' call in
  'false-if-exception'.
* tests/gexp.scm ("printer", "printer vs. ungexp-splicing"): New tests.

gexp: Resolve the default system at '>>=' time.

Partly fixes <http://bugs.gnu.org/18002>.
Reported by David Thompson <dthompson2@worcester.edu>.

* guix/gexp.scm (gexp->derivation): Change #:system to default #f.
  Use (%current-system) from within the 'mlet*'.
* tests/gexp.scm ("gexp->derivation, default system"): New test.

monads: Fix 'mapm' so that effects happen from left to right.

* guix/monads.scm (mapm): Don't reverse LST, so that items are processed
  from left to right.  Bind the result of 'foldm' and reverse it.
* tests/monads.scm ("sequence"): Change 'frob' so it performs its side
  effect within an 'mlet' body.  Adjust call accordingly.

build: Get the canonical $HOME name when testing 'guix package'.

* tests/guix-package.sh (HOME): Recompute using 'pwd -P'.

build: Support running the test suite from a directory with symlinks.

Fixes <http://bugs.gnu.org/17935>.
Reported by Alex Kost <alezost@gmail.com>.

* test-env.in: Canonicalize $NIX_STORE_DIR, and remove
  $NIX_IGNORE_SYMLINK_STORE setting.
* tests/guix-register.sh: Likewise, canonicalize $new_store_dir and
  $new_store and leave $NIX_IGNORE_SYMLINK_STORE unchanged.

guix package: Do the right thing for '-p ~/.guix-profile'.

Fixes <http://bugs.gnu.org/17939>.
Reported by Taylan Ulrich Bayirli/Kammer <taylanbayirli@gmail.com>.

* guix/scripts/package.scm (canonicalize-profile): New procedure.
  (%options): Use it for --profile.
* tests/guix-package.sh: Add test.

guix {system,offload}: Improve reporting of syntax errors.

* guix/scripts/system.scm (read-operating-system) <catch handler>: Add
  case for 'syntax-error'.  Correct message for default case.
* guix/scripts/offload.scm (build-machines) <catch handler>: Add case
  for 'syntax-error'.
* tests/guix-system.sh: New file.
* Makefile.am (SH_TESTS): Add it.

tests: Use the C locale for 'guix package -s'.

* tests/guix-package.sh: Set LC_MESSAGES=C before the 'guix package -s'
  test.

Merge branch 'master' into core-updates

guix build: Allow gexps to be passed to '-e'.

* guix/ui.scm (%guix-user-module): New variable.
  (read/eval): Pass it as the second argument to 'eval'.
* guix/scripts/build.scm (options/resolve-packages): Add case for
  'gexp?'.
* tests/guix-build.sh: Add tests.
* doc/guix.texi (Invoking guix build): Document '-e gexp'.
guxi build: Allow gexps to be passed to '-e'.

* guix/ui.scm (%guix-user-module): New variable.
  (read/eval): Pass it as the second argument to 'eval'.
* guix/scripts/build.scm (options/resolve-packages): Add case for
  'gexp?'.
* tests/guix-build.sh: Add tests.
* doc/guix.texi (Invoking guix build): Document '-e gexp'.

Merge branch 'master' into core-updates

tests: Skip tests that would hit the shebang length limitation.

* tests/gexp.scm (shebang): New variable.
  Skip "gexp->script" when SHEBANG is longer than 127 chars.
* guix/gexp.scm (gexp->script): Add comment on the issue.

derivations: Add #:allowed-references 'derivation' parameter.

* guix/derivations.scm (derivation): Add #:allowed-references
  parameter.
  [user+system-env-vars]: Honor it.
* tests/derivations.scm ("derivation #:allowed-references, ok",
  "derivation #:allowed-references, not allowed",
  "derivation #:allowed-references, self allowed",
  "derivation #:allowed-references, self not allowed"): New tests.
* doc/guix.texi (Derivations): Document #:allowed-references.

Merge branch 'master' into core-updates

syscalls: Be more permissive in 'umount' test.

* tests/syscalls.scm ("umount, ENOENT"): Rename to...
  ("umount, ENOENT/EPERM"): ... this.  Accept EPERM as a valid return
  value.