Taken from Debian. Updated by Alex Griffin.

Author: Dmitry Shachnev <mitya57@gmail.com>
Description: do not build unrar extension as we strip unrar from the tarball
Forwarded: not-needed
Last-Update: 2013-04-04

Index: calibre/setup/extensions.py
===================================================================
--- calibre.orig/setup/extensions.json	2016-07-21 21:21:05.000000000 -0500
+++ calibre/setup/extensions.json	2016-07-27 11:22:17.167710112 -0500
@@ -211,14 +211,5 @@
         "sources": "calibre/devices/mtp/unix/devices.c calibre/devices/mtp/unix/libmtp.c",
         "headers": "calibre/devices/mtp/unix/devices.h calibre/devices/mtp/unix/upstream/music-players.h calibre/devices/mtp/unix/upstream/device-flags.h",
         "libraries": "mtp"
-    },
-    {
-        "name": "unrar",
-        "sources": "unrar/rar.cpp unrar/strlist.cpp unrar/strfn.cpp unrar/pathfn.cpp unrar/savepos.cpp unrar/smallfn.cpp unrar/global.cpp unrar/file.cpp unrar/filefn.cpp unrar/filcreat.cpp unrar/archive.cpp unrar/arcread.cpp unrar/unicode.cpp unrar/system.cpp unrar/isnt.cpp unrar/crypt.cpp unrar/crc.cpp unrar/rawread.cpp unrar/encname.cpp unrar/resource.cpp unrar/match.cpp unrar/timefn.cpp unrar/rdwrfn.cpp unrar/consio.cpp unrar/options.cpp unrar/ulinks.cpp unrar/errhnd.cpp unrar/rarvm.cpp unrar/secpassword.cpp unrar/rijndael.cpp unrar/getbits.cpp unrar/sha1.cpp unrar/extinfo.cpp unrar/extract.cpp unrar/volume.cpp unrar/list.cpp unrar/find.cpp unrar/unpack.cpp unrar/cmddata.cpp unrar/filestr.cpp unrar/scantree.cpp calibre/utils/unrar.cpp",
-        "inc_dirs": "unrar",
-        "defines": "SILENT RARDLL UNRAR _FILE_OFFSET_BITS=64 _LARGEFILE_SOURCE",
-        "windows_defines": "SILENT RARDLL UNRAR",
-        "optimize_level": 2,
-        "windows_libraries": "User32 Advapi32 kernel32 Shell32"
     }
 ]
 
 
Index: calibre/src/calibre/ebooks/metadata/archive.py
===================================================================
--- calibre.orig/src/calibre/ebooks/metadata/archive.py	2016-07-21 21:21:05.000000000 -0500
+++ calibre/src/calibre/ebooks/metadata/archive.py	2016-07-27 11:21:07.793616039 -0500
@@ -42,7 +42,7 @@
     description = _('Extract common e-book formats from archives '
         '(zip/rar) files. Also try to autodetect if they are actually '
         'cbz/cbr files.')
-    file_types = set(['zip', 'rar'])
+    file_types = set(['zip'])
     supported_platforms = ['windows', 'osx', 'linux']
     on_import = True