Libguestfs - Nov 2019 - [PATCH nbdkit] python: Print readable tracebacks

We used traceback.format_exception, returning traceback lines. Join the
lines to make the tracebacks more readable.

Here is an example traceback:

$ ./nbdkit -f -v python tests/python-exception.py
...
nbdkit: debug: python: config_complete
nbdkit: error: tests/python-exception.py: config_complete: error: Traceback
(most recent call last):
   File "tests/python-exception.py", line 51, in config_complete
    raise RuntimeError("this is the test string")
 RuntimeError: this is the test string
---
 plugins/python/python.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/python/python.c b/plugins/python/python.c
index 148097f..71fa2e3 100644
--- a/plugins/python/python.c
+++ b/plugins/python/python.c
@@ -167,7 +167,7 @@ print_python_traceback (const char *callback,
                                      type, error, traceback, NULL);
   if (rv == NULL)
     return -1;
-  traceback_str = PyObject_Str (rv);
+  traceback_str = PyUnicode_Join (NULL, rv);
   Py_DECREF (rv);
   traceback_cstr = python_to_string (traceback_str);
   if (traceback_cstr == NULL) {
-- 
2.21.0

On Sat, Nov 23, 2019 at 05:06:41AM +0200, Nir Soffer
wrote:
> We used traceback.format_exception, returning traceback lines. Join the
> lines to make the tracebacks more readable.
> 
> Here is an example traceback:
> 
> $ ./nbdkit -f -v python tests/python-exception.py
> ...
> nbdkit: debug: python: config_complete
> nbdkit: error: tests/python-exception.py: config_complete: error: Traceback
(most recent call last):
>    File "tests/python-exception.py", line 51, in config_complete
>     raise RuntimeError("this is the test string")
>  RuntimeError: this is the test string
> ---
>  plugins/python/python.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/plugins/python/python.c b/plugins/python/python.c
> index 148097f..71fa2e3 100644
> --- a/plugins/python/python.c
> +++ b/plugins/python/python.c
> @@ -167,7 +167,7 @@ print_python_traceback (const char *callback,
>                                       type, error, traceback, NULL);
>    if (rv == NULL)
>      return -1;
> -  traceback_str = PyObject_Str (rv);
> +  traceback_str = PyUnicode_Join (NULL, rv);
>    Py_DECREF (rv);
>    traceback_cstr = python_to_string (traceback_str);
>    if (traceback_cstr == NULL) {
ACK and pushed, thanks.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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