From 7547b3eb11c1df040b04d72fb27ac5156b2f2c42 Mon Sep 17 00:00:00 2001
From: Rebecca Turner <rturner@starry.com>
Date: Tue, 9 Nov 2021 11:48:44 -0500
Subject: [PATCH] Fix marker parsing with pyparsing 3.0.5

Closes #486

Context in pyparsing: https://github.com/pyparsing/pyparsing/issues/110#issuecomment-963167729
---
 packaging/requirements.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/packaging/requirements.py b/packaging/requirements.py
index 53f9a3aa..d7d7dd42 100644
--- a/packaging/requirements.py
+++ b/packaging/requirements.py
@@ -67,9 +67,7 @@ class InvalidRequirement(ValueError):
 VERSION_SPEC.setParseAction(lambda s, l, t: t[1])
 
 MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
-MARKER_EXPR.setParseAction(
-    lambda s, l, t: Marker(s[t._original_start : t._original_end])
-)
+MARKER_EXPR.addParseAction(lambda s, l, t: Marker(t[0]))
 MARKER_SEPARATOR = SEMICOLON
 MARKER = MARKER_SEPARATOR + MARKER_EXPR