diff -Nru libdebian-installer-0.120/debian/changelog libdebian-installer-0.120+rpi1/debian/changelog
--- libdebian-installer-0.120/debian/changelog	2019-08-14 18:49:28.000000000 +0000
+++ libdebian-installer-0.120+rpi1/debian/changelog	2021-01-08 00:12:02.000000000 +0000
@@ -1,3 +1,10 @@
+libdebian-installer (0.120+rpi1) bullseye-staging; urgency=medium
+
+  * Increase readsize to deal with metadata of rust-winapi (Closes: 971946)
+    (thanks to Jonathan Stanley)
+
+ -- Peter Michael Green <plugwash@raspbian.org>  Fri, 08 Jan 2021 00:12:02 +0000
+
 libdebian-installer (0.120) unstable; urgency=medium
 
   * Team upload.
diff -Nru libdebian-installer-0.120/src/parser_rfc822.c libdebian-installer-0.120+rpi1/src/parser_rfc822.c
--- libdebian-installer-0.120/src/parser_rfc822.c	2019-05-28 21:51:16.000000000 +0000
+++ libdebian-installer-0.120+rpi1/src/parser_rfc822.c	2021-01-08 00:11:51.000000000 +0000
@@ -35,7 +35,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#define READSIZE 65536
+#define READSIZE 262144
 
 int di_parser_rfc822_read (char *begin, size_t size, di_parser_info *info, di_parser_read_entry_new entry_new, di_parser_read_entry_finish entry_finish, void *user_data)
 {