Update dbg.py

src/relenv_gdb/dbg.py

@@ -1,21 +1,20 @@
-# Copyright 2023 VMware, Inc.
-# SPDX-License-Identifier: Apache-2.0
 """
 Use gdb to pull python stack traces for every thread in a parent process and all of it's children.
 """
 import os
-import pprint
-import subprocess
 import sys
+import subprocess
+import pprint
 import tempfile
+import pathlib
 
 import psutil
 
 CMD_TPL = """
 set pagination off
 set logging file {output}
 set logging enabled on
-source libpython.py
+source {libpython}
 echo --- thread info for pid {pid} ---\\n
 
 info threads
@@ -32,35 +31,45 @@
 quit
 """
 
+def find_dist_info():
+    for name in pathlib.Path(__file__).parent.parent.rglob("relenv_gdb*dist-info"):
+        return name
+
+def find_relenv_gdb():
+    dist_info = find_dist_info()
+    text = pathlib.Path(dist_info, "RECORD").read_text()
+    for line in text.split("\n"):
+        if "bin/relenv-gdb" in line:
+            location, digest, size = line.rsplit(",", 2)
+            script = (pathlib.Path(dist_info).parent / location).resolve()
+            if script.exists():
+                return script
 
 def append_line(path, line):
-    """
-    Append a line of text to the file.
-    """
     with open(path, "a") as fp:
         fp.write(line + "\n")
 
 
-def debug(proc, output):
-    """
-    Debug a process.
-    """
+def debug(gdb, proc, output):
     print(f"Debugging {proc.pid} {' '.join(proc.cmdline())}")
     fd, path = tempfile.mkstemp()
     with open(path, "w") as fp:
-        fp.write(CMD_TPL.format(output=output, pid=proc.pid))
+        fp.write(
+            CMD_TPL.format(
+                output=output,
+                pid=proc.pid,
+                libpython=(pathlib.Path(__file__).parent / "libpython.py").resolve(),
+            )
+        )
     append_line(output, f"===[ begin {proc.pid} ]===")
     append_line(output, pprint.pformat(proc.as_dict()))
-    subprocess.run(["gdb", "-p", f"{proc.pid}", "--command", path], capture_output=True)
+    subprocess.run([gdb, "-p", f"{proc.pid}", "--command", path], capture_output=True)
     append_line(output, f"===[ end {proc.pid} ]===")
     os.close(fd)
     os.remove(path)
 
 
 def main():
-    """
-    The dbg program entry point.
-    """
     try:
         pid = int(sys.argv[1])
     except (IndexError, ValueError):
@@ -71,9 +80,12 @@ def main():
         print("Please provide a valid pid as the only argument")
         sys.exit(1)
 
+    gdb = find_relenv_gdb()
+    if not gdb:
+        print("Unable to find relenv-gdb script")
     output = "gdb-output.txt"
 
-    debug(parent, output)
+    debug(gdb, parent, output)
 
     for child in parent.children():
         debug(child, output)