Don't forget to install zlib

JakubVanek · JakubVanek · commit 6e898abc19af · 2018-01-06T11:38:06.000+01:00
diff --git a/build/Dockerfile b/build/Dockerfile
@@ -45,7 +45,8 @@ RUN dpkg --add-architecture armel && \
         autoconf-archive \
         automake \
         autotools-dev \
-        mercurial
+        mercurial \
+        zlib1g-dev
 
 
 # copy build patches & scripts
