WIP: sandbox bwrap state

This is probably going to need a more substantial refactor - the job
pickler probably shouldn't be reaching into the individual sandboxes
classes like this.

Ideally the state would be stored somewhere more accessible than class
attributes.

2 files changed, 42 insertions, 2 deletions

diff --git a/src/buildstream/_scheduler/jobs/jobpickler.py b/src/buildstream/_scheduler/jobs/jobpickler.py
index b0465ec9e..ce8e4a687 100644
--- a/src/buildstream/_scheduler/jobs/jobpickler.py
+++ b/src/buildstream/_scheduler/jobs/jobpickler.py
@@ -56,9 +56,11 @@ def pickle_child_job(child_job, projects):
     # Note that we need to consider all the state of the program that's
     # necessary for the job, this includes e.g. the global state of the node
     # module.
+    from ...sandbox._sandboxbwrap import SandboxBwrap
+    sandbox_bwrap_state = SandboxBwrap.save_check_available_status()
     node_module_state = node._get_state_for_pickling()
     return _pickle_child_job_data(
-        (child_job, node_module_state),
+        (child_job, node_module_state, sandbox_bwrap_state),
         projects,
     )
 
@@ -77,8 +79,12 @@ def pickle_child_job(child_job, projects):
 def do_pickled_child_job(pickled, *child_args):
     utils._is_main_process = _not_main_process
 
-    child_job, node_module_state = pickle.load(pickled)
+    child_job, node_module_state, sandbox_bwrap_state = pickle.load(pickled)
     node._set_state_from_pickling(node_module_state)
+
+    from ...sandbox._sandboxbwrap import SandboxBwrap
+    SandboxBwrap.load_check_available_status(sandbox_bwrap_state)
+
     return child_job.child_action(*child_args)
 
 
diff --git a/src/buildstream/sandbox/_sandboxbwrap.py b/src/buildstream/sandbox/_sandboxbwrap.py
index bd60eafc1..7911c59f9 100644
--- a/src/buildstream/sandbox/_sandboxbwrap.py
+++ b/src/buildstream/sandbox/_sandboxbwrap.py
@@ -92,6 +92,40 @@ class SandboxBwrap(Sandbox):
 
         cls.user_ns_available = cls._check_user_ns_available()
 
+    @classmethod
+    def save_check_available_status(cls):
+        # Note, these ones only get set if bwrap is available:
+        #
+        #     cls._uid = os.geteuid()
+        #     cls._gid = os.getegid()
+        #     cls.user_ns_available = cls._check_user_ns_available()
+        #
+        return (
+            cls._bwrap_exists,
+            cls._die_with_parent_available,
+            cls._dummy_reasons,
+            cls._gid,
+            cls._have_fuse,
+            cls._have_good_bwrap,
+            cls._json_status_available,
+            cls._uid,
+            cls.user_ns_available,
+        )
+
+    @classmethod
+    def load_check_available_status(cls, state):
+        (
+            cls._bwrap_exists,
+            cls._die_with_parent_available,
+            cls._dummy_reasons,
+            cls._gid,
+            cls._have_fuse,
+            cls._have_good_bwrap,
+            cls._json_status_available,
+            cls._uid,
+            cls.user_ns_available,
+        ) = state
+
     @staticmethod
     def _check_user_ns_available():
         # Here, lets check if bwrap is able to create user namespaces,