wip: attempt to handle github PR builds

docs/source/conf.py

@@ -110,6 +110,10 @@ def linkcode_resolve(domain, info):
         lineno = inspect.getsourcelines(obj)[1]
         filename = (inspect.getsourcefile(obj)
                     or f"{filename}.py").split("vllm/", 1)[1]
+        pr_number = os.environ.get('GITHUB_REF')
+        if pr_number and pr_number.startswith('refs/pull/'):
+            pr_number = pr_number.split('/')[2]
+            return f"https://github.com/vllm-project/vllm/pull/{pr_number}/files#diff-{filename}#L{lineno}"
         return f"https://github.com/vllm-project/vllm/blob/main/{filename}#L{lineno}"
     except Exception:
         return f"https://github.com/vllm-project/vllm/blob/main/{filename}.py"