From 6f6a7636d4340d7233654f2bd9cfbdb9024356fa Mon Sep 17 00:00:00 2001
From: Miro Hrončok <miro@hroncok.cz>
Date: Oct 01 2020 14:35:08 +0000
Subject: Skip empty lines from tox deps


An empty line happens when there are not deps:

    Handling  from tox --print-deps-only: <toxname>
    WARNING: Skipping invalid requirement:
        Parse error at "''": Expected W:(abcd...)

---

diff --git a/pyproject_buildrequires.py b/pyproject_buildrequires.py
index 36139eb..a34c9e2 100644
--- a/pyproject_buildrequires.py
+++ b/pyproject_buildrequires.py
@@ -235,7 +235,7 @@ def parse_tox_requires_lines(lines):
                 f'WARNING: Skipping dependency line: {line}\n'
                 + f'    tox deps options other than -r are not supported (yet).',
             )
-        else:
+        elif line:
             packages.append(line)
     return packages