--- ./src/libarchive/CMakeLists.txt.orig
+++ ./src/libarchive/CMakeLists.txt
@@ -843,7 +843,7 @@
 # aggressive about diagnosing build problems; this can get
 # relaxed somewhat in final shipping versions.
 IF ("CMAKE_C_COMPILER_ID" MATCHES "^GNU$")
-  ADD_DEFINITIONS(-Wall -Werror)
+  ADD_DEFINITIONS(-Wall)
 ENDIF ("CMAKE_C_COMPILER_ID" MATCHES "^GNU$")
 
 IF(ENABLE_TEST)