From: Scott Worley <scottworley@scottworley.com>
Date: Fri, 9 Jul 2021 22:30:27 +0000 (-0700)
Subject: Appease linter: No global variables
X-Git-Tag: v3.0.5~4
X-Git-Url: http://git.scottworley.com/pinch/commitdiff_plain/b1e8c1b07e325426febd7e27030e4f8f6769bcde?ds=sidebyside;hp=ffe4974c09bb1fd7e559a0caf4109c260cb67a79

Appease linter: No global variables
---

diff --git a/pinch.py b/pinch.py
index c26070b..9555d74 100644
--- a/pinch.py
+++ b/pinch.py
@@ -302,18 +302,17 @@ def digest_file(filename: str) -> Digest16:
     return Digest16(hasher.hexdigest())
 
 
-_experimental_flag_needed = None
+@functools.lru_cache
+def _experimental_flag_needed(v: Verification) -> bool:
+    v.status('Checking Nix version')
+    process = subprocess.run(['nix', '--help'], stdout=subprocess.PIPE)
+    v.result(process.returncode == 0)
+    return b'--experimental-features' in process.stdout
 
 
 def _nix_command(v: Verification) -> List[str]:
-    global _experimental_flag_needed
-    if _experimental_flag_needed is None:
-        v.status('Checking Nix version')
-        process = subprocess.run(['nix', '--help'], stdout=subprocess.PIPE)
-        v.result(process.returncode == 0)
-        _experimental_flag_needed = b'--experimental-features' in process.stdout
     return ['nix', '--experimental-features',
-            'nix-command'] if _experimental_flag_needed else ['nix']
+            'nix-command'] if _experimental_flag_needed(v) else ['nix']
 
 
 def to_Digest16(v: Verification, digest32: Digest32) -> Digest16: