Fix find_rust_extension syntax not allowed in Python 2.7

Signed-off-by: Martin Larralde <[email protected]>

Author: Martin Larralde

example_tomlgen/README.rst

@@ -55,7 +55,7 @@ The authors list is generated after the ``author`` and ``author_email`` options
 from ``setup.py`` / ``setup.cfg``, but can also be overriden using the
 ``authors`` key in the ``[tomlgen_rust]`` section of ``setup.cfg``:
 
-.. code-block:: toml
+.. code-block:: ini
 
     [tomlgen_rust]
     authors =
@@ -108,7 +108,7 @@ add ``Cargo.toml`` and ``Cargo.lock`` to your ``.gitignore`` file.
 Then, make sure ``tomlgen_rust`` is run before ``build_rust`` everytime by
 adding aliases to your ``setup.cfg`` file:
 
-.. code-block:: toml
+.. code-block:: ini
 
     [aliases]
     build_rust = tomlgen_rust -f build_rust

setuptools_rust/tomlgen.py

@@ -159,7 +159,7 @@ def _slugify(name):
     slug = [char if char in allowed else '_' for char in name]
     return ''.join(slug)
 
-def find_rust_extensions(*directories, libfile="lib.rs", **kwargs):
+def find_rust_extensions(*directories, **kwargs):
     """Attempt to find Rust extensions in given directories.
 
     This function will recurse through the directories in the given
@@ -206,9 +206,13 @@ def find_rust_extensions(*directories, libfile="lib.rs", **kwargs):
             lib.mylib.rustext => lib/mylib/rustext/Cargo.toml
     """
 
+    # Get the file used to mark a Rust extension
+    libfile = kwargs.get('libfile', 'lib.rs')
+
+    # Get the directories to explore
     directories = directories or [os.getcwd()]
-    extensions = []
 
+    extensions = []
     for directory in directories:
         for base, dirs, files in os.walk(directory):
             if libfile in files: