termux-packages/packages/pkgfile/src-update.c.patch

--- a/src/update.c
+++ b/src/update.c
@@ -360,7 +360,7 @@
 
   tmpdir = getenv("TMPDIR");
   if (tmpdir == NULL) {
-    tmpdir = "/tmp";
+    tmpdir = "@TERMUX_PREFIX@/tmp";
   }
 
 #ifdef O_TMPFILE