sandbox: Reinitialize class when pickle is used

Class data is not pickled and thus, class variables set by
`check_available()` are not set when `check_sandbox_config()` is called
by a job subprocess.

2 files changed, 8 insertions, 0 deletions

diff --git a/src/buildstream/sandbox/_sandboxbuildboxrun.py b/src/buildstream/sandbox/_sandboxbuildboxrun.py
index 7f35213af..80858f338 100644
--- a/src/buildstream/sandbox/_sandboxbuildboxrun.py
+++ b/src/buildstream/sandbox/_sandboxbuildboxrun.py
@@ -61,6 +61,10 @@ class SandboxBuildBoxRun(SandboxREAPI):
 
     @classmethod
     def check_sandbox_config(cls, platform, config):
+        if platform.does_multiprocessing_start_require_pickling():
+            # Reinitialize class as class data is not pickled.
+            cls.check_available()
+
         # Check host os and architecture match
         if config.build_os != platform.get_host_os():
             raise SandboxError("Configured and host OS don't match.")
diff --git a/src/buildstream/sandbox/_sandboxbwrap.py b/src/buildstream/sandbox/_sandboxbwrap.py
index 851cc0969..216145938 100644
--- a/src/buildstream/sandbox/_sandboxbwrap.py
+++ b/src/buildstream/sandbox/_sandboxbwrap.py
@@ -107,6 +107,10 @@ class SandboxBwrap(Sandbox):
 
     @classmethod
     def check_sandbox_config(cls, local_platform, config):
+        if local_platform.does_multiprocessing_start_require_pickling():
+            # Reinitialize class as class data is not pickled.
+            cls.check_available()
+
         if not cls.user_ns_available:
             # Without user namespace support, the UID/GID in the sandbox
             # will match the host UID/GID.