Solution of https://gist.github.com/4374324. It could happen to make it compiled with more strict option. This svn diff was taken under src/lib.

svn diff of common.c

Index: libfetch/common.c
===================================================================
--- libfetch/common.c   (revision 244684)
+++ libfetch/common.c   (working copy)
@@ -327,6 +327,8 @@
 #ifdef WITH_SSL
        int ret, ssl_err;
 
+       SSL_METHOD*meth;
+
        /* Init the SSL library and context */
        if (!SSL_library_init()){
                fprintf(stderr, "SSL library init failed\n");
@@ -335,8 +337,8 @@
 
        SSL_load_error_strings();
 
-       conn->ssl_meth = SSLv23_client_method();
-       conn->ssl_ctx = SSL_CTX_new(conn->ssl_meth);
+       conn->ssl_meth = meth = SSLv23_client_method();
+       conn->ssl_ctx = SSL_CTX_new(meth);
        SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
 
        conn->ssl = SSL_new(conn->ssl_ctx);