According to documentation upstream build scripts only look for these
packages to try and guess whether support for them has been enabled
in app-text/sword.

--- a/platforms/common/core/core.pro
+++ b/platforms/common/core/core.pro
@@ -173,13 +173,5 @@
 # Clucene
 include(../../common/clucene/clucene.pro)
 
-# CURL
-# optional
-curl:include(../../common/curl/curl.pro)
-
-# ICU
-# optional
-icu:include(../../common/icu/icu.pro)
-
 # Sword
 include(../../common/sword/sword.pro)