# HG changeset patch
# User Raphaël Gomès <rgomes@octobus.net>
# Date 2019-10-07 21:17:44
# Node ID 97097897557438e6bda24934a5d059d383b5aa93
# Parent  98d996a138defcb43e3f5bc27f159c5b277bd3ee

rust-utils: introduce a debug util to print the python stack trace

Differential Revision: https://phab.mercurial-scm.org/D7057

diff --git a/rust/hg-cpython/src/lib.rs b/rust/hg-cpython/src/lib.rs
--- a/rust/hg-cpython/src/lib.rs
+++ b/rust/hg-cpython/src/lib.rs
@@ -35,6 +35,7 @@ pub mod discovery;
 pub mod exceptions;
 pub mod filepatterns;
 pub mod parsers;
+pub mod utils;
 
 py_module_initializer!(rustext, initrustext, PyInit_rustext, |py, m| {
     m.add(
diff --git a/rust/hg-cpython/src/utils.rs b/rust/hg-cpython/src/utils.rs
new file mode 100644
--- /dev/null
+++ b/rust/hg-cpython/src/utils.rs
@@ -0,0 +1,13 @@
+use cpython::{PyDict, PyObject, PyResult, PyTuple, Python};
+
+#[allow(unused)]
+pub fn print_python_trace(py: Python) -> PyResult<PyObject> {
+    eprintln!("===============================");
+    eprintln!("Printing Python stack from Rust");
+    eprintln!("===============================");
+    let traceback = py.import("traceback")?;
+    let sys = py.import("sys")?;
+    let kwargs = PyDict::new(py);
+    kwargs.set_item(py, "file", sys.get(py, "stderr")?)?;
+    traceback.call(py, "print_stack", PyTuple::new(py, &[]), Some(&kwargs))
+}