Merge branch 'raoul/775-execution-environment-reqs' into 'master'

Execution environment reqs

Closes #775

See merge request BuildStream/buildstream!969

61 files changed, 389 insertions, 94 deletions

diff --git a/buildstream/_options/optionarch.py b/buildstream/_options/optionarch.py
index 13a691643..1d8509cf2 100644
--- a/buildstream/_options/optionarch.py
+++ b/buildstream/_options/optionarch.py
@@ -17,7 +17,7 @@
 #  Authors:
 #        Tristan Van Berkom <tristan.vanberkom@codethink.co.uk>
 
-import os
+from .._platform import Platform
 from .optionenum import OptionEnum
 
 
@@ -41,8 +41,7 @@ class OptionArch(OptionEnum):
         super(OptionArch, self).load(node, allow_default_definition=False)
 
     def load_default_value(self, node):
-        _, _, _, _, machine_arch = os.uname()
-        return machine_arch
+        return Platform.get_host_arch()
 
     def resolve(self):
 
diff --git a/buildstream/_options/optionos.py b/buildstream/_options/optionos.py
new file mode 100644
index 000000000..e76cf177c
--- /dev/null
+++ b/buildstream/_options/optionos.py
@@ -0,0 +1,41 @@
+
+#
+#  Copyright (C) 2017 Codethink Limited
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
+#
+#  Authors:
+#        Raoul Hidalgo Charman <raoul.hidalgocharman@codethink.co.uk>
+
+import os
+from .optionenum import OptionEnum
+
+
+# OptionOS
+#
+class OptionOS(OptionEnum):
+
+    OPTION_TYPE = 'os'
+
+    def load(self, node):
+        super(OptionOS, self).load(node, allow_default_definition=False)
+
+    def load_default_value(self, node):
+        return os.uname()[0]
+
+    def resolve(self):
+
+        # Validate that the default OS reported by uname() is explicitly
+        # supported by the project, if not overridden by user config or cli.
+        self.validate(self.value)
diff --git a/buildstream/_options/optionpool.py b/buildstream/_options/optionpool.py
index 1274586f7..3132af564 100644
--- a/buildstream/_options/optionpool.py
+++ b/buildstream/_options/optionpool.py
@@ -28,6 +28,7 @@ from .optionenum import OptionEnum
 from .optionflags import OptionFlags
 from .optioneltmask import OptionEltMask
 from .optionarch import OptionArch
+from .optionos import OptionOS
 
 
 _OPTION_TYPES = {
@@ -36,6 +37,7 @@ _OPTION_TYPES = {
     OptionFlags.OPTION_TYPE: OptionFlags,
     OptionEltMask.OPTION_TYPE: OptionEltMask,
     OptionArch.OPTION_TYPE: OptionArch,
+    OptionOS.OPTION_TYPE: OptionOS,
 }
 
 
diff --git a/buildstream/_platform/linux.py b/buildstream/_platform/linux.py
index 33f3966c1..702059a5d 100644
--- a/buildstream/_platform/linux.py
+++ b/buildstream/_platform/linux.py
@@ -25,6 +25,7 @@ from .. import utils
 from ..sandbox import SandboxDummy
 
 from . import Platform
+from .._exceptions import PlatformError
 
 
 class Linux(Platform):
@@ -58,6 +59,9 @@ class Linux(Platform):
         else:
             self._user_ns_available = False
 
+        # Set linux32 option
+        self._linux32 = False
+
     def create_sandbox(self, *args, **kwargs):
         if not self._local_sandbox_available:
             return self._create_dummy_sandbox(*args, **kwargs)
@@ -71,11 +75,33 @@ class Linux(Platform):
 
         if self._user_ns_available:
             # User namespace support allows arbitrary build UID/GID settings.
-            return True
-        else:
+            pass
+        elif (config.build_uid != self._uid or config.build_gid != self._gid):
             # Without user namespace support, the UID/GID in the sandbox
             # will match the host UID/GID.
-            return config.build_uid == self._uid and config.build_gid == self._gid
+            return False
+
+        # We can't do builds for another host or architecture except x86-32 on
+        # x86-64
+        host_os = self.get_host_os()
+        host_arch = self.get_host_arch()
+        if config.build_os != host_os:
+            raise PlatformError("Configured and host OS don't match.")
+        elif config.build_arch != host_arch:
+            # We can use linux32 for building 32bit on 64bit machines
+            if (host_os == "Linux" and
+                    ((config.build_arch == "x86-32" and host_arch == "x86-64") or
+                     (config.build_arch == "aarch32" and host_arch == "aarch64"))):
+                # check linux32 is available
+                try:
+                    utils.get_host_tool('linux32')
+                    self._linux32 = True
+                except utils.ProgramNotFoundError:
+                    pass
+            else:
+                raise PlatformError("Configured architecture and host architecture don't match.")
+
+        return True
 
     ################################################
     #              Private Methods                 #
@@ -100,6 +126,7 @@ class Linux(Platform):
         kwargs['user_ns_available'] = self._user_ns_available
         kwargs['die_with_parent_available'] = self._die_with_parent_available
         kwargs['json_status_available'] = self._json_status_available
+        kwargs['linux32'] = self._linux32
         return SandboxBwrap(*args, **kwargs)
 
     def _check_user_ns_available(self):
diff --git a/buildstream/_platform/platform.py b/buildstream/_platform/platform.py
index d3e4b949a..42b360ff8 100644
--- a/buildstream/_platform/platform.py
+++ b/buildstream/_platform/platform.py
@@ -73,6 +73,44 @@ class Platform():
         else:
             return min(cpu_count, cap)
 
+    @staticmethod
+    def get_host_os():
+        return os.uname()[0]
+
+    # get_host_arch():
+    #
+    # This returns the architecture of the host machine. The possible values
+    # map from uname -m in order to be a OS independent list.
+    #
+    # Returns:
+    #    (string): String representing the architecture
+    @staticmethod
+    def get_host_arch():
+        # get the hardware identifier from uname
+        uname_machine = os.uname()[4]
+        uname_to_arch = {
+            "aarch64": "aarch64",
+            "aarch64_be": "aarch64-be",
+            "amd64": "x86-64",
+            "arm": "aarch32",
+            "armv8l": "aarch64",
+            "armv8b": "aarch64-be",
+            "i386": "x86-32",
+            "i486": "x86-32",
+            "i586": "x86-32",
+            "i686": "x86-32",
+            "ppc64": "power-isa-be",
+            "ppc64le": "power-isa-le",
+            "sparc": "sparc-v9",
+            "sparc64": "sparc-v9",
+            "x86_64": "x86-64"
+        }
+        try:
+            return uname_to_arch[uname_machine]
+        except KeyError:
+            raise PlatformError("uname gave unsupported machine architecture: {}"
+                                .format(uname_machine))
+
     ##################################################################
     #                        Sandbox functions                       #
     ##################################################################
diff --git a/buildstream/_platform/unix.py b/buildstream/_platform/unix.py
index d2acefe65..bbc55c3af 100644
--- a/buildstream/_platform/unix.py
+++ b/buildstream/_platform/unix.py
@@ -44,4 +44,13 @@ class Unix(Platform):
     def check_sandbox_config(self, config):
         # With the chroot sandbox, the UID/GID in the sandbox
         # will match the host UID/GID (typically 0/0).
-        return config.build_uid == self._uid and config.build_gid == self._gid
+        if config.build_uid != self._uid or config.build_gid != self._gid:
+            return False
+
+        # Check host os and architecture match
+        if config.build_os != self.get_host_os():
+            raise PlatformError("Configured and host OS don't match.")
+        elif config.build_arch != self.get_host_arch():
+            raise PlatformError("Configured and host architecture don't match.")
+
+        return True
diff --git a/buildstream/element.py b/buildstream/element.py
index 2f724f49d..27677b054 100644
--- a/buildstream/element.py
+++ b/buildstream/element.py
@@ -2410,6 +2410,11 @@ class Element(Plugin):
             project.ensure_fully_loaded()
             sandbox_config = _yaml.node_chain_copy(project._sandbox)
 
+        # Get the platform to ask for host architecture
+        platform = Platform.get_platform()
+        host_arch = platform.get_host_arch()
+        host_os = platform.get_host_os()
+
         # The default config is already composited with the project overrides
         sandbox_defaults = _yaml.node_get(self.__defaults, Mapping, 'sandbox', default_value={})
         sandbox_defaults = _yaml.node_chain_copy(sandbox_defaults)
@@ -2419,10 +2424,13 @@ class Element(Plugin):
         _yaml.node_final_assertions(sandbox_config)
 
         # Sandbox config, unlike others, has fixed members so we should validate them
-        _yaml.node_validate(sandbox_config, ['build-uid', 'build-gid'])
+        _yaml.node_validate(sandbox_config, ['build-uid', 'build-gid', 'build-os', 'build-arch'])
 
-        return SandboxConfig(self.node_get_member(sandbox_config, int, 'build-uid'),
-                             self.node_get_member(sandbox_config, int, 'build-gid'))
+        return SandboxConfig(
+            self.node_get_member(sandbox_config, int, 'build-uid'),
+            self.node_get_member(sandbox_config, int, 'build-gid'),
+            self.node_get_member(sandbox_config, str, 'build-os', default=host_os),
+            self.node_get_member(sandbox_config, str, 'build-arch', default=host_arch))
 
     # This makes a special exception for the split rules, which
     # elements may extend but whos defaults are defined in the project.
diff --git a/buildstream/sandbox/_config.py b/buildstream/sandbox/_config.py
index 5debe24b2..457f92b3c 100644
--- a/buildstream/sandbox/_config.py
+++ b/buildstream/sandbox/_config.py
@@ -16,7 +16,6 @@
 #
 #  Authors:
 #        Jim MacArthur <jim.macarthur@codethink.co.uk>
-import os
 
 
 # SandboxConfig
@@ -24,9 +23,11 @@ import os
 # A container for sandbox configuration data. We want the internals
 # of this to be opaque, hence putting it in its own private file.
 class SandboxConfig():
-    def __init__(self, build_uid, build_gid):
+    def __init__(self, build_uid, build_gid, build_os=None, build_arch=None):
         self.build_uid = build_uid
         self.build_gid = build_gid
+        self.build_os = build_os
+        self.build_arch = build_arch
 
     # get_unique_key():
     #
@@ -45,10 +46,9 @@ class SandboxConfig():
         # However this should be the right place to support
         # such configurations in the future.
         #
-        operating_system, _, _, _, machine_arch = os.uname()
         unique_key = {
-            'os': operating_system,
-            'arch': machine_arch
+            'os': self.build_os,
+            'arch': self.build_arch
         }
 
         # Avoid breaking cache key calculation with
diff --git a/buildstream/sandbox/_sandboxbwrap.py b/buildstream/sandbox/_sandboxbwrap.py
index f7b11326a..d2abc33d0 100644
--- a/buildstream/sandbox/_sandboxbwrap.py
+++ b/buildstream/sandbox/_sandboxbwrap.py
@@ -57,6 +57,7 @@ class SandboxBwrap(Sandbox):
         self.user_ns_available = kwargs['user_ns_available']
         self.die_with_parent_available = kwargs['die_with_parent_available']
         self.json_status_available = kwargs['json_status_available']
+        self.linux32 = kwargs['linux32']
 
     def _run(self, command, flags, *, cwd, env):
         stdout, stderr = self._get_output()
@@ -74,8 +75,14 @@ class SandboxBwrap(Sandbox):
         mount_map = MountMap(self, flags & SandboxFlags.ROOT_READ_ONLY)
         root_mount_source = mount_map.get_mount_source('/')
 
+        # start command with linux32 if needed
+        if self.linux32:
+            bwrap_command = [utils.get_host_tool('linux32')]
+        else:
+            bwrap_command = []
+
         # Grab the full path of the bwrap binary
-        bwrap_command = [utils.get_host_tool('bwrap')]
+        bwrap_command += [utils.get_host_tool('bwrap')]
 
         for k, v in env.items():
             bwrap_command += ['--setenv', k, v]
diff --git a/buildstream/sandbox/_sandboxremote.py b/buildstream/sandbox/_sandboxremote.py
index c366b3f40..a967629fe 100644
--- a/buildstream/sandbox/_sandboxremote.py
+++ b/buildstream/sandbox/_sandboxremote.py
@@ -126,13 +126,20 @@ class SandboxRemote(Sandbox):
                                  EnvironmentVariable(name=k, value=v)
                                  for (k, v) in environment.items()]
 
+        config = self._get_config()
+        platform = remote_execution_pb2.Platform()
+        platform.properties.extend([remote_execution_pb2.Platform.
+                                    Property(name="OSFamily", value=config.build_os),
+                                    remote_execution_pb2.Platform.
+                                    Property(name="ISA", value=config.build_arch)])
+
         # Create and send the Command object.
         remote_command = remote_execution_pb2.Command(arguments=command,
                                                       working_directory=working_directory,
                                                       environment_variables=environment_variables,
                                                       output_files=[],
                                                       output_directories=[self._output_directory],
-                                                      platform=None)
+                                                      platform=platform)
         context = self._get_context()
         cascache = context.get_cascache()
         casremote = CASRemote(self.storage_remote_spec)
diff --git a/doc/examples/flatpak-autotools/elements/base/sdk.bst b/doc/examples/flatpak-autotools/elements/base/sdk.bst
index a1b6c5856..97089b83b 100644
--- a/doc/examples/flatpak-autotools/elements/base/sdk.bst
+++ b/doc/examples/flatpak-autotools/elements/base/sdk.bst
@@ -5,10 +5,10 @@ sources:
   url: gnomesdk:repo/
   gpg-key: keys/gnome-sdk.gpg
   (?):
-  - arch == "x86_64":
+  - arch == "x86-64":
       track: runtime/org.freedesktop.BaseSdk/x86_64/1.4
       ref: 0d9d255d56b08aeaaffb1c820eef85266eb730cb5667e50681185ccf5cd7c882
-  - arch == "i386":
+  - arch == "x86-32":
       track: runtime/org.freedesktop.BaseSdk/i386/1.4
       ref: 16036b747c1ec8e7fe291f5b1f667cb942f0267d08fcad962e9b7627d6cf1981
 config:
diff --git a/doc/examples/flatpak-autotools/project.conf b/doc/examples/flatpak-autotools/project.conf
index 0296b22f6..401dc561a 100644
--- a/doc/examples/flatpak-autotools/project.conf
+++ b/doc/examples/flatpak-autotools/project.conf
@@ -10,6 +10,6 @@ options:
     type: arch
     description: The machine architecture
     values:
-    - x86_64
-    - i386
+    - x86-64
+    - x86-32
 
diff --git a/doc/source/format_declaring.rst b/doc/source/format_declaring.rst
index e1ad4f720..57ea4488a 100644
--- a/doc/source/format_declaring.rst
+++ b/doc/source/format_declaring.rst
@@ -294,8 +294,10 @@ can be viewed in detail in the :ref:`builtin public data <public_builtin>` secti
 Sandbox
 ~~~~~~~
 Configuration for the build sandbox (other than :ref:`environment variables <format_environment>`)
-can be placed in the ``sandbox`` configuration. At present, only the
-UID and GID used by the user in the group can be specified.
+can be placed in the ``sandbox`` configuration. The UID and GID used by the user
+in the group can be specified, as well as the desired OS and machine
+architecture. Possible machine architecture follow the same list as specified in
+the :ref:`architecture option <project_options_arch>`.
 
 .. code:: yaml
 
@@ -311,6 +313,24 @@ you can supply a different uid or gid for the sandbox. Only
 bwrap-style sandboxes support custom user IDs at the moment, and hence
 this will only work on Linux host platforms.
 
+.. code:: yaml
+
+   # Specify build OS and architecture
+   sandbox:
+     build-os: AIX
+     build-arch: power-isa-be
+
+When building locally, if these don't match the host machine then generally the
+build will fail. The exception is when the OS is Linux and the architecture
+specifies an ``x86-32`` build on an ``x86-64`` machine, or ``aarch32`` build on
+a ``aarch64`` machine, in which case the ``linux32`` command is prepended to the
+bubblewrap command.
+
+When building remotely, the OS and architecture are added to the ``Platform``
+field in the ``Command`` uploaded. Whether this actually results in a building
+the element for the desired OS and architecture is dependent on the server
+having implemented these options the same as buildstream.
+
 .. note::
 
    The ``sandbox`` configuration is available since :ref:`format version 6 <project_format_version>`
diff --git a/doc/source/format_project.rst b/doc/source/format_project.rst
index 9b51f8d4b..59ee05e85 100644
--- a/doc/source/format_project.rst
+++ b/doc/source/format_project.rst
@@ -552,9 +552,22 @@ exported as a comma separated list of selected value strings.
 
 Architecture
 ~~~~~~~~~~~~
-The ``arch`` option type is special enumeration option which
-defaults to the result of `uname -m`, and does not support
-assigning any default in the project configuration.
+The ``arch`` option type is a special enumeration option which defaults via
+`uname -m` results to the following list.
+
+* aarch32
+* aarch64
+* aarch64-be
+* power-isa-be
+* power-isa-le
+* sparc-v9
+* x86-32
+* x86-64
+
+The reason for this, opposed to using just `uname -m`, is that we want an
+OS-independent list, as well as several results mapping to the same architecture
+(e.g. i386, i486 etc. are all x86-32). It does not support assigning any default
+in the project configuration.
 
 .. code:: yaml
 
@@ -563,16 +576,40 @@ assigning any default in the project configuration.
        type: arch
        description: The machine architecture
        values:
-       - arm
+       - aarch32
        - aarch64
-       - i386
-       - x86_64
+       - x86-32
+       - x86-64
 
 
 Architecture options can be tested with the same expressions
 as other Enumeration options.
 
 
+.. _project_options_os:
+
+OS
+~~
+
+The ``os`` option type is a special enumeration option, which defaults to the
+results of `uname -s`. It does not support assigning any default in the project
+configuration.
+
+.. code:: yaml
+
+    options:
+      machine_os:
+        type: os
+        description: The machine OS
+        values:
+        - Linux
+        - SunOS
+        - Darwin
+        - FreeBSD
+
+Os options can be tested with the same expressions as other Enumeration options.
+
+
 .. _project_options_element_mask:
 
 Element mask
diff --git a/tests/cachekey/cachekey.py b/tests/cachekey/cachekey.py
index 113f5bab0..c278b9ca9 100644
--- a/tests/cachekey/cachekey.py
+++ b/tests/cachekey/cachekey.py
@@ -144,7 +144,7 @@ DATA_DIR = os.path.join(
 # The cache key test uses a project which exercises all plugins,
 # so we cant run it at all if we dont have them installed.
 #
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
                     reason='Cache keys depend on architecture')
 @pytest.mark.skipif(not IS_LINUX, reason='Only available on linux')
 @pytest.mark.skipif(HAVE_BZR is False, reason="bzr is not available")
diff --git a/tests/cachekey/project/elements/build1.expected b/tests/cachekey/project/elements/build1.expected
index 27d9595e8..ef18ad98b 100644
--- a/tests/cachekey/project/elements/build1.expected
+++ b/tests/cachekey/project/elements/build1.expected
@@ -1 +1 @@
-ce0ddf7126d45d14f5ec1a525337c39ec8ddbbe4b0ec2ef51bae777619ed39bb
\ No newline at end of file
+a0d000abc1dea8714cd27f348d0b798b35e7246c44e330c4b3f7912fabacc6db
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/build2.expected b/tests/cachekey/project/elements/build2.expected
index 21328c966..015085d9e 100644
--- a/tests/cachekey/project/elements/build2.expected
+++ b/tests/cachekey/project/elements/build2.expected
@@ -1 +1 @@
-5e2a48dbeae43f6bab84071dbd02345a3aa32a473c189645ab26f3d5d6cfe547
\ No newline at end of file
+79f546a78748d943a6958c99ab4ad03305f96fefd0b424b6b246b0c9816e00c6
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/compose1.expected b/tests/cachekey/project/elements/compose1.expected
index a76ce029f..2bb7802d7 100644
--- a/tests/cachekey/project/elements/compose1.expected
+++ b/tests/cachekey/project/elements/compose1.expected
@@ -1 +1 @@
-b63c517f604e8ca64e973476f687190d14a813a0bf77573b93a557f5fb7ae214
\ No newline at end of file
+36cb2ac57281343959266e87913eb690f4c68980d7267160ff5f071db778719d
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/compose2.expected b/tests/cachekey/project/elements/compose2.expected
index cc17908c7..4b03402cb 100644
--- a/tests/cachekey/project/elements/compose2.expected
+++ b/tests/cachekey/project/elements/compose2.expected
@@ -1 +1 @@
-6676f1cce86166eb66ab83254fe2deb43be93644967de110dd42713dea181508
\ No newline at end of file
+30ffe86750a497052f8fc868c47a08644cd579f8e86f59be9b04fa5530b6a9b6
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/compose3.expected b/tests/cachekey/project/elements/compose3.expected
index cef7e620a..5b975be25 100644
--- a/tests/cachekey/project/elements/compose3.expected
+++ b/tests/cachekey/project/elements/compose3.expected
@@ -1 +1 @@
-0f8f444566c097067f2dfa54f26100abff85cc49bf9acf0081129f53244bc144
\ No newline at end of file
+1bac1d17cc2aed85ab14daf264f955b2204823799bc5bac5ff77c79b32d0c08b
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/compose4.expected b/tests/cachekey/project/elements/compose4.expected
index 96cb1c4a0..48a96844a 100644
--- a/tests/cachekey/project/elements/compose4.expected
+++ b/tests/cachekey/project/elements/compose4.expected
@@ -1 +1 @@
-aa72331d42f647e845243e8a77389febfb78acff09f70771a3545bdf0d4d70ad
\ No newline at end of file
+99690e3a915f4c5b6f76a5bcee8bffe74d077a4398ac29623be36bca26703290
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/compose5.expected b/tests/cachekey/project/elements/compose5.expected
index 6fec106a3..40287aa87 100644
--- a/tests/cachekey/project/elements/compose5.expected
+++ b/tests/cachekey/project/elements/compose5.expected
@@ -1 +1 @@
-37bb4486f42e04b8a1c9f9cb9358adfd0d4dae0bb3b2a4072e090848cd2b955d
\ No newline at end of file
+a3e25dabe35a2909920f94c9e457c977b00dfa49c161b82c47ad55e761349c6a
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/import1.expected b/tests/cachekey/project/elements/import1.expected
index 8e3c582e7..ab07f28da 100644
--- a/tests/cachekey/project/elements/import1.expected
+++ b/tests/cachekey/project/elements/import1.expected
@@ -1 +1 @@
-ce2dce59ad7fa810c945e7385cc25d4c8992adf71fbdc44336cf136330fe2b16
\ No newline at end of file
+791aaae474dce95f98c849d748088697334a9b4bfcb6225c59804efe03e803c9
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/import2.expected b/tests/cachekey/project/elements/import2.expected
index 5ad1b5816..8b7327e20 100644
--- a/tests/cachekey/project/elements/import2.expected
+++ b/tests/cachekey/project/elements/import2.expected
@@ -1 +1 @@
-4fd32ee29026ecbcee717c8f04a0b807934a7042d67b8786e0eb9326757c845d
\ No newline at end of file
+3aaf0565ffbeb2faa4e48230d07ef839b9bc2ff012780ca9b5f6b9c968f539b2
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/import3.expected b/tests/cachekey/project/elements/import3.expected
index c5d55728f..05cfbdf2e 100644
--- a/tests/cachekey/project/elements/import3.expected
+++ b/tests/cachekey/project/elements/import3.expected
@@ -1 +1 @@
-e24dd31bda628616138014391a94040490da0820a2c42ab10ec6dfad1b694df9
\ No newline at end of file
+7cadfb9b592af06fa765389278d919cb8e29515ad057710563da9cd1c36e2ce9
\ No newline at end of file
diff --git a/tests/cachekey/project/elements/script1.expected b/tests/cachekey/project/elements/script1.expected
index 83dbba964..71a53906c 100644
--- a/tests/cachekey/project/elements/script1.expected
+++ b/tests/cachekey/project/elements/script1.expected
@@ -1 +1 @@
-a139b184c8dd6a6e08231822ca2d886688e5d7720dc2290f8876d485bdb920b5
\ No newline at end of file
+14db0665eed7c3d4cf3685c2e386a9e494465927a5ad962c98b92856be3d88b8
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/bzr1.expected b/tests/cachekey/project/sources/bzr1.expected
index 81bcac7ec..debfe0c9d 100644
--- a/tests/cachekey/project/sources/bzr1.expected
+++ b/tests/cachekey/project/sources/bzr1.expected
@@ -1 +1 @@
-d2aeb3715c5842461384bea6a9bcf452310d1626ae40b6e7a9f51adc66a270fd
\ No newline at end of file
+faadf63e4025e4a068532d01296b65db38dbf2c95625695832f7c601b2134375
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/git1.expected b/tests/cachekey/project/sources/git1.expected
index dca2d04f0..5a98e679f 100644
--- a/tests/cachekey/project/sources/git1.expected
+++ b/tests/cachekey/project/sources/git1.expected
@@ -1 +1 @@
-4e03d21335e578034b09191ebf4977f0f537425c3031805dfb2f835ff77925cd
\ No newline at end of file
+3dc6b7c47ddb3ced44c42d22f4c192b9245112197172d2f9ce9498e4614bbca4
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/git2.expected b/tests/cachekey/project/sources/git2.expected
index d32c44557..bfccc82c2 100644
--- a/tests/cachekey/project/sources/git2.expected
+++ b/tests/cachekey/project/sources/git2.expected
@@ -1 +1 @@
-75c96f6c8d3ca3ffe164cd51f42689287021e60ef524f56340539feadd5a9fb8
\ No newline at end of file
+3ded0e77f43c43f86920012d6ffe0e2f0cd98908ceab7023bf5a8d34bedf1d6e
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/git3.expected b/tests/cachekey/project/sources/git3.expected
index b383ccbfc..c0ab92c20 100644
--- a/tests/cachekey/project/sources/git3.expected
+++ b/tests/cachekey/project/sources/git3.expected
@@ -1 +1 @@
-6a25f539bd8629a36399c58efd2f5c9c117feb845076a37dc321b55d456932b6
\ No newline at end of file
+31e95bdf97eb85d2261c988de7ee055e00c31a76199b495643661e5d1fbd195e
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/local1.expected b/tests/cachekey/project/sources/local1.expected
index 8e3c582e7..ab07f28da 100644
--- a/tests/cachekey/project/sources/local1.expected
+++ b/tests/cachekey/project/sources/local1.expected
@@ -1 +1 @@
-ce2dce59ad7fa810c945e7385cc25d4c8992adf71fbdc44336cf136330fe2b16
\ No newline at end of file
+791aaae474dce95f98c849d748088697334a9b4bfcb6225c59804efe03e803c9
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/local2.expected b/tests/cachekey/project/sources/local2.expected
index ffa2c5d51..f59f4a7cf 100644
--- a/tests/cachekey/project/sources/local2.expected
+++ b/tests/cachekey/project/sources/local2.expected
@@ -1 +1 @@
-de18b7d9ee2358d6924db5a9f72257e2e2a3d5f8450cb8891f8984bfd1101345
\ No newline at end of file
+e44b20eaec873dd28471963d789fbb5660eb14754b7711a5ab0d7785d3bffd37
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/ostree1.expected b/tests/cachekey/project/sources/ostree1.expected
index f12da1ba1..7bfd2ee12 100644
--- a/tests/cachekey/project/sources/ostree1.expected
+++ b/tests/cachekey/project/sources/ostree1.expected
@@ -1 +1 @@
-b8414e0077057fcac4e10291d88d898d7132dc591e3b265afee1ad59831815ca
\ No newline at end of file
+3b13c4a4b3adcfdf2b6bbbc8b74cc8f43cbfd39ec73af1b285bd8fef79a57068
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/patch1.expected b/tests/cachekey/project/sources/patch1.expected
index b193eca9f..1a2a1a782 100644
--- a/tests/cachekey/project/sources/patch1.expected
+++ b/tests/cachekey/project/sources/patch1.expected
@@ -1 +1 @@
-a426c94443da29b060af0aed3f2ffdd4470e1ce9cb0592d8696c55a767e448c1
\ No newline at end of file
+ffad4c89efdbcabb86aeea338b4d076f9f44dec2b7b0bc0e6ede39a0e792f992
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/patch2.expected b/tests/cachekey/project/sources/patch2.expected
index 94e975ae2..3a6812987 100644
--- a/tests/cachekey/project/sources/patch2.expected
+++ b/tests/cachekey/project/sources/patch2.expected
@@ -1 +1 @@
-b884e246b61cc930f33216055e99a82a47dcf42435b860622039555a159fc255
\ No newline at end of file
+5e91946c032a83120ae97a84f96dbfbf98992d6decff99df0073a117cd45702e
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/patch3.expected b/tests/cachekey/project/sources/patch3.expected
index 4e11c37ce..ba20eb320 100644
--- a/tests/cachekey/project/sources/patch3.expected
+++ b/tests/cachekey/project/sources/patch3.expected
@@ -1 +1 @@
-79e297df970b6faaa1cfd64e5a6b6c8b4611b9128a19a7f22a2ee051174fccc9
\ No newline at end of file
+bd55bfb2b546b57ac627ba7756269e5d64cb7a74c990e0ef66c06bd4dc3b44a3
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/pip1.expected b/tests/cachekey/project/sources/pip1.expected
index 1fe5a50c4..a85714052 100644
--- a/tests/cachekey/project/sources/pip1.expected
+++ b/tests/cachekey/project/sources/pip1.expected
@@ -1 +1 @@
-d8bdc8848e4d2e3d70a1267e73bf0e63afa778e4c905cad1a94308634176fb87
\ No newline at end of file
+09d873158f35ea64e67919373a6cfbd4aaba9321b817c89317b1350da8267318
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/remote1.expected b/tests/cachekey/project/sources/remote1.expected
index 751816322..2595e6f4c 100644
--- a/tests/cachekey/project/sources/remote1.expected
+++ b/tests/cachekey/project/sources/remote1.expected
@@ -1 +1 @@
-2ab4d2a2490dabafadfc44d95b78f690105e0f0d1cb58665a6a332920172741e
\ No newline at end of file
+fc9d09695a6e04785671cc53e36dbc1dd1391a8bcd4a7003c5cce161f2a6c484
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/remote2.expected b/tests/cachekey/project/sources/remote2.expected
index 9b0428eb6..1de8e1b76 100644
--- a/tests/cachekey/project/sources/remote2.expected
+++ b/tests/cachekey/project/sources/remote2.expected
@@ -1 +1 @@
-642cbafb3020ab80dae274a983ade81757cf3a1fa4fbba01f621599830be50fd
\ No newline at end of file
+de35773c4cec65912e4cef18682a0fc176a49ee6637b0c5e8f68b546225c0865
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/tar1.expected b/tests/cachekey/project/sources/tar1.expected
index 64addbfe1..7575b52b3 100644
--- a/tests/cachekey/project/sources/tar1.expected
+++ b/tests/cachekey/project/sources/tar1.expected
@@ -1 +1 @@
-d32bf753f0507f07c8b660ed8fc4428434faf7d07049de92ee203256db0149a3
\ No newline at end of file
+9e2e12cb32b52463fd324afe2f32b622ee76973cdefcb35e0a14c8d0ecf94604
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/tar2.expected b/tests/cachekey/project/sources/tar2.expected
index 9b4372330..e2e8e36c1 100644
--- a/tests/cachekey/project/sources/tar2.expected
+++ b/tests/cachekey/project/sources/tar2.expected
@@ -1 +1 @@
-41844c597dbffb4f3dcfaae2e5553836816b1b77744db01e47671ab14276795a
\ No newline at end of file
+08b95e17d08ac792e04df9d8165a00ee11520f022895cc6abafe379295a55fc3
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/zip1.expected b/tests/cachekey/project/sources/zip1.expected
index ac53a32d5..faef2458b 100644
--- a/tests/cachekey/project/sources/zip1.expected
+++ b/tests/cachekey/project/sources/zip1.expected
@@ -1 +1 @@
-a68328d4ad389a4cdc690103bc6b0bb4d2252eb4f738f6cd004645eb478fcf41
\ No newline at end of file
+590963540c16c9c462fbbed88d1c6bf9134e753c652e01710b81d6218bf348bb
\ No newline at end of file
diff --git a/tests/cachekey/project/sources/zip2.expected b/tests/cachekey/project/sources/zip2.expected
index 3da5f68a7..950b5002f 100644
--- a/tests/cachekey/project/sources/zip2.expected
+++ b/tests/cachekey/project/sources/zip2.expected
@@ -1 +1 @@
-30c104c539200d568f9157549dd3c8a15a157cb5c56632638b99986e4edf0576
\ No newline at end of file
+97dc236aa4f600cfbe6f5d7d47841f547ac6c6ee0e6b55275af8d3f1ec2cb68a
\ No newline at end of file
diff --git a/tests/cachekey/project/target.expected b/tests/cachekey/project/target.expected
index 0c89af6bb..00ac2beeb 100644
--- a/tests/cachekey/project/target.expected
+++ b/tests/cachekey/project/target.expected
@@ -1 +1 @@
-bc99c288f855ac2619787f0067223f7812d2e10a9d2c7f2bf47de7113c0fd25c
\ No newline at end of file
+d6d283ed1fb0467fcfa5bf69f8596d0f0ac6638281bc9d8e52e1212e2ec0bcab
\ No newline at end of file
diff --git a/tests/examples/autotools.py b/tests/examples/autotools.py
index e7ca8c5e9..8e4bf5a75 100644
--- a/tests/examples/autotools.py
+++ b/tests/examples/autotools.py
@@ -13,8 +13,8 @@ DATA_DIR = os.path.join(
 
 
 # Tests a build of the autotools amhello project on a alpine-linux base runtime
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_autotools_build(cli, tmpdir, datafiles):
@@ -38,8 +38,8 @@ def test_autotools_build(cli, tmpdir, datafiles):
 
 
 # Test running an executable built with autotools.
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_autotools_run(cli, tmpdir, datafiles):
diff --git a/tests/examples/developing.py b/tests/examples/developing.py
index 4bb7076c5..0a51802a9 100644
--- a/tests/examples/developing.py
+++ b/tests/examples/developing.py
@@ -14,8 +14,8 @@ DATA_DIR = os.path.join(
 
 
 # Test that the project builds successfully
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_autotools_build(cli, tmpdir, datafiles):
@@ -37,8 +37,8 @@ def test_autotools_build(cli, tmpdir, datafiles):
 
 
 # Test the unmodified hello command works as expected.
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_run_unmodified_hello(cli, tmpdir, datafiles):
@@ -70,8 +70,8 @@ def test_open_workspace(cli, tmpdir, datafiles):
 
 
 # Test making a change using the workspace
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_make_change_in_workspace(cli, tmpdir, datafiles):
diff --git a/tests/examples/flatpak-autotools.py b/tests/examples/flatpak-autotools.py
index dbaf522a2..73910c5eb 100644
--- a/tests/examples/flatpak-autotools.py
+++ b/tests/examples/flatpak-autotools.py
@@ -32,8 +32,8 @@ def workaround_setuptools_bug(project):
 
 # Test that a build upon flatpak runtime 'works' - we use the autotools sample
 # amhello project for this.
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_OSTREE, reason='Only available on linux with ostree')
 @pytest.mark.datafiles(DATA_DIR)
 def test_autotools_build(cli, tmpdir, datafiles):
@@ -57,8 +57,8 @@ def test_autotools_build(cli, tmpdir, datafiles):
 
 
 # Test running an executable built with autotools
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_OSTREE, reason='Only available on linux with ostree')
 @pytest.mark.datafiles(DATA_DIR)
 def test_autotools_run(cli, tmpdir, datafiles):
diff --git a/tests/examples/integration-commands.py b/tests/examples/integration-commands.py
index f4b0405e0..71e383008 100644
--- a/tests/examples/integration-commands.py
+++ b/tests/examples/integration-commands.py
@@ -12,8 +12,8 @@ DATA_DIR = os.path.join(
 )
 
 
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_integration_commands_build(cli, tmpdir, datafiles):
@@ -25,8 +25,8 @@ def test_integration_commands_build(cli, tmpdir, datafiles):
 
 
 # Test running the executable
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_integration_commands_run(cli, tmpdir, datafiles):
diff --git a/tests/examples/junctions.py b/tests/examples/junctions.py
index 97c622bbd..753fa2dc0 100644
--- a/tests/examples/junctions.py
+++ b/tests/examples/junctions.py
@@ -13,8 +13,8 @@ DATA_DIR = os.path.join(
 
 
 # Test that the project builds successfully
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_build(cli, tmpdir, datafiles):
@@ -25,8 +25,8 @@ def test_build(cli, tmpdir, datafiles):
 
 
 # Test the callHello script works as expected.
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_shell_call_hello(cli, tmpdir, datafiles):
diff --git a/tests/examples/running-commands.py b/tests/examples/running-commands.py
index 3e679f9c2..61e23fd9c 100644
--- a/tests/examples/running-commands.py
+++ b/tests/examples/running-commands.py
@@ -12,8 +12,8 @@ DATA_DIR = os.path.join(
 )
 
 
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_running_commands_build(cli, tmpdir, datafiles):
@@ -25,8 +25,8 @@ def test_running_commands_build(cli, tmpdir, datafiles):
 
 
 # Test running the executable
-@pytest.mark.skipif(MACHINE_ARCH != 'x86_64',
-                    reason='Examples are writtent for x86_64')
+@pytest.mark.skipif(MACHINE_ARCH != 'x86-64',
+                    reason='Examples are writtent for x86-64')
 @pytest.mark.skipif(not IS_LINUX or not HAVE_BWRAP, reason='Only available on linux with bubblewrap')
 @pytest.mark.datafiles(DATA_DIR)
 def test_running_commands_run(cli, tmpdir, datafiles):
diff --git a/tests/format/list-directive-type-error/project.conf b/tests/format/list-directive-type-error/project.conf
index 1dd0f1b0a..79f73402b 100644
--- a/tests/format/list-directive-type-error/project.conf
+++ b/tests/format/list-directive-type-error/project.conf
@@ -4,4 +4,4 @@ options:
   arch:
     type: arch
     description: Example architecture option
-    values: [ x86_32, x86_64, aarch64 ]
+    values: [ x86-32, x86-64, aarch64 ]
\ No newline at end of file
diff --git a/tests/format/option-arch/element.bst b/tests/format/option-arch/element.bst
index 4da01d889..2528d9170 100644
--- a/tests/format/option-arch/element.bst
+++ b/tests/format/option-arch/element.bst
@@ -2,7 +2,7 @@ kind: autotools
 variables:
   result: "Nothing"
   (?):
-  - machine_arch == "arm":
+  - machine_arch == "aarch32":
       result: "Army"
   - machine_arch == "aarch64":
       result: "Aarchy"
diff --git a/tests/format/option-arch/project.conf b/tests/format/option-arch/project.conf
index a2c3ddf9a..8b94232cf 100644
--- a/tests/format/option-arch/project.conf
+++ b/tests/format/option-arch/project.conf
@@ -5,5 +5,5 @@ options:
     type: arch
     description: The machine architecture
     values:
-    - arm
+    - aarch32
     - aarch64
diff --git a/tests/format/option-os/element.bst b/tests/format/option-os/element.bst
new file mode 100644
index 000000000..8208d67e8
--- /dev/null
+++ b/tests/format/option-os/element.bst
@@ -0,0 +1,12 @@
+kind: autotools
+variables:
+  result: "Nothing"
+  (?):
+  - machine_os == "Linux":
+      result: "Linuxy"
+  - machine_os == "Darwin":
+      result: "Darwiny"
+  - machine_os == "SunOS":
+      result: "SunOSy"
+  - machine_os == "FreeBSD":
+      result: "FreeBSDy"
\ No newline at end of file
diff --git a/tests/format/option-os/project.conf b/tests/format/option-os/project.conf
new file mode 100644
index 000000000..5edb5072f
--- /dev/null
+++ b/tests/format/option-os/project.conf
@@ -0,0 +1,11 @@
+name: test
+
+options:
+  machine_os:
+    type: os
+    description: The operating system
+    values:
+    - Linux
+    - Darwin
+    - FreeBSD
+    - SunOS
diff --git a/tests/format/optionarch.py b/tests/format/optionarch.py
index 4c126aa87..901b6e2da 100644
--- a/tests/format/optionarch.py
+++ b/tests/format/optionarch.py
@@ -29,7 +29,7 @@ def override_uname_arch(name):
 @pytest.mark.datafiles(DATA_DIR)
 @pytest.mark.parametrize("uname,value,expected", [
     # Test explicitly provided arches
-    ('arm', 'arm', 'Army'),
+    ('arm', 'aarch32', 'Army'),
     ('arm', 'aarch64', 'Aarchy'),
 
     # Test automatically derived arches
@@ -38,7 +38,7 @@ def override_uname_arch(name):
 
     # Test that explicitly provided arches dont error out
     # when the `uname` reported arch is not supported
-    ('i386', 'arm', 'Army'),
+    ('i386', 'aarch32', 'Army'),
     ('x86_64', 'aarch64', 'Aarchy'),
 ])
 def test_conditional(cli, datafiles, uname, value, expected):
diff --git a/tests/format/optionos.py b/tests/format/optionos.py
new file mode 100644
index 000000000..b05d7e49e
--- /dev/null
+++ b/tests/format/optionos.py
@@ -0,0 +1,76 @@
+import os
+import pytest
+from contextlib import contextmanager
+
+from buildstream import _yaml
+from buildstream._exceptions import ErrorDomain, LoadErrorReason
+from tests.testutils.runcli import cli
+
+DATA_DIR = os.path.dirname(os.path.realpath(__file__))
+
+
+@contextmanager
+def override_uname_os(name):
+    orig_uname = os.uname
+    orig_tuple = tuple(os.uname())
+    override_result = (name, orig_tuple[1],
+                       orig_tuple[2], orig_tuple[3],
+                       orig_tuple[4])
+
+    def override():
+        return override_result
+
+    os.uname = override
+    yield
+    os.uname = orig_uname
+
+
+@pytest.mark.datafiles(DATA_DIR)
+@pytest.mark.parametrize("uname,value,expected", [
+    # Test explicitly provided arches
+    ('Darwin', 'Linux', 'Linuxy'),
+    ('SunOS', 'FreeBSD', 'FreeBSDy'),
+
+    # Test automatically derived arches
+    ('Linux', None, 'Linuxy'),
+    ('Darwin', None, 'Darwiny'),
+
+    # Test that explicitly provided arches dont error out
+    # when the `uname` reported arch is not supported
+    ('AIX', 'Linux', 'Linuxy'),
+    ('HaikuOS', 'SunOS', 'SunOSy'),
+])
+def test_conditionals(cli, datafiles, uname, value, expected):
+    with override_uname_os(uname):
+        project = os.path.join(datafiles.dirname, datafiles.basename, 'option-os')
+
+        bst_args = []
+        if value is not None:
+            bst_args += ['--option', 'machine_os', value]
+
+        bst_args += [
+            'show',
+            '--deps', 'none',
+            '--format', '%{vars}',
+            'element.bst'
+        ]
+        result = cli.run(project=project, silent=True, args=bst_args)
+        result.assert_success()
+
+        loaded = _yaml.load_data(result.output)
+        assert loaded['result'] == expected
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_unsupported_arch(cli, datafiles):
+
+    with override_uname_os("AIX"):
+        project = os.path.join(datafiles.dirname, datafiles.basename, 'option-os')
+        result = cli.run(project=project, silent=True, args=[
+            'show',
+            '--deps', 'none',
+            '--format', '%{vars}',
+            'element.bst'
+        ])
+
+        result.assert_main_error(ErrorDomain.LOAD, LoadErrorReason.INVALID_DATA)
diff --git a/tests/integration/base/generate-base.sh b/tests/integration/base/generate-base.sh
index d1ebd58ae..338c6d98f 100755
--- a/tests/integration/base/generate-base.sh
+++ b/tests/integration/base/generate-base.sh
@@ -9,7 +9,7 @@
 
 set -eux
 
-ALPINE_ARCH=${ARCH:-x86_64}
+ALPINE_ARCH=${ARCH:-x86-64}
 ALPINE_BASE=http://dl-cdn.alpinelinux.org/alpine/v3.7/releases/${ALPINE_ARCH}/alpine-minirootfs-3.7.0-${ALPINE_ARCH}.tar.gz
 
 mkdir root
diff --git a/tests/integration/project/elements/base/base-alpine.bst b/tests/integration/project/elements/base/base-alpine.bst
index dd5ee7d88..c5833095d 100644
--- a/tests/integration/project/elements/base/base-alpine.bst
+++ b/tests/integration/project/elements/base/base-alpine.bst
@@ -9,7 +9,7 @@ sources:
   - kind: tar
     base-dir: ''
     (?):
-    - arch == "x86_64":
+    - arch == "x86-64":
         ref: 3eb559250ba82b64a68d86d0636a6b127aa5f6d25d3601a79f79214dc9703639
         url: "alpine:integration-tests-base.v1.x86_64.tar.xz"
     - arch == "aarch64":
diff --git a/tests/integration/project/project.conf b/tests/integration/project/project.conf
index e0475539a..726f65686 100644
--- a/tests/integration/project/project.conf
+++ b/tests/integration/project/project.conf
@@ -13,7 +13,7 @@ options:
     type: arch
     description: Current architecture
     values:
-      - x86_64
+      - x86-64
       - aarch64
 split-rules:
   test:
diff --git a/tests/testutils/site.py b/tests/testutils/site.py
index 6c286e720..c7625cccf 100644
--- a/tests/testutils/site.py
+++ b/tests/testutils/site.py
@@ -5,6 +5,7 @@ import os
 import sys
 
 from buildstream import _site, utils, ProgramNotFoundError
+from buildstream._platform import Platform
 
 try:
     utils.get_host_tool('bzr')
@@ -52,4 +53,4 @@ except ImportError:
 
 IS_LINUX = os.getenv('BST_FORCE_BACKEND', sys.platform).startswith('linux')
 
-_, _, _, _, MACHINE_ARCH = os.uname()
+MACHINE_ARCH = Platform.get_host_arch()