utils.py: Catch correctly if a process is dead when trying to kill it

Before, we would throw an exception that the process is not dead yet if
it happened to die at the exact moment we tried to access it.

This ensures we don't throw exceptions in such cases, since the process
would be already dead, as we wanted

1 files changed, 12 insertions, 2 deletions

diff --git a/src/buildstream/utils.py b/src/buildstream/utils.py
index 9c6761ccc..438543b83 100644
--- a/src/buildstream/utils.py
+++ b/src/buildstream/utils.py
@@ -1295,7 +1295,12 @@ def _tempnamedfile_name(dir):  # pylint: disable=redefined-builtin
 #    pid (int): Process ID
 #
 def _kill_process_tree(pid):
-    proc = psutil.Process(pid)
+    try:
+        proc = psutil.Process(pid)
+    except psutil.NoSuchProcess:
+        # Process already died, we're good
+        return
+
     children = proc.children(recursive=True)
 
     def kill_proc(p):
@@ -1352,7 +1357,12 @@ def _call(*popenargs, terminate=False, **kwargs):
             # Some callers know that their subprocess can be
             # gracefully terminated, make an attempt first
             if terminate:
-                proc = psutil.Process(process.pid)
+                try:
+                    proc = psutil.Process(process.pid)
+                except psutil.NoSuchProcess:
+                    # Nothing to do, the process already terminated
+                    return
+
                 proc.terminate()
 
                 try: