From 57cfa05166a224443f24579b98cd954d8dc96439 Mon Sep 17 00:00:00 2001
From: Tzu-ping Chung <uranusjr@gmail.com>
Date: Sun, 25 Apr 2021 04:47:23 +0800
Subject: [PATCH] Set project name to UNKNOWN when empty

For compatibility with distutils
---
 src/pip/_internal/locations/_sysconfig.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pip/_internal/locations/_sysconfig.py b/src/pip/_internal/locations/_sysconfig.py
index e4d66d25d24..9b034091366 100644
--- a/src/pip/_internal/locations/_sysconfig.py
+++ b/src/pip/_internal/locations/_sysconfig.py
@@ -139,7 +139,7 @@ def get_scheme(
     scheme = Scheme(
         platlib=paths["platlib"],
         purelib=paths["purelib"],
-        headers=os.path.join(paths["include"], dist_name),
+        headers=os.path.join(paths["include"], dist_name or "UNKNOWN"),
         scripts=paths["scripts"],
         data=paths["data"],
     )