From b896966bd140bc9c3c965c70597517ede83d5b86 Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Sat, 13 Jun 2020 00:24:24 -0700
Subject: [PATCH 1/1] Use type rather than field presence

---
 pinch.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pinch.py b/pinch.py
index 34c63f1..bfc6ac6 100644
--- a/pinch.py
+++ b/pinch.py
@@ -578,10 +578,10 @@ def update(args: argparse.Namespace) -> None:
     exprs: Dict[str, str] = {}
     config = read_config_files(args.channels_file)
     for section in config:
-        if 'alias_of' in config[section]:
+        sp = read_search_path(config[section])
+        if isinstance(sp, AliasSearchPath):
             assert 'git_repo' not in config[section]
             continue
-        sp = read_search_path(config[section])
         tarball = sp.fetch(v, section, config[section])
         exprs[section] = (
             'f: f { name = "%s"; channelName = "%%s"; src = builtins.storePath "%s"; }' %
-- 
2.44.1