[vlc-devel] Error loading module

[francesco at bltitalia.com]

I'm experiencing this error when vlc attempts to load module:

alfredo at alfredo-Z97N-WIFI:~/vlc-2.2.5.1$ ./vlc -vvv --list
VLC media player 2.2.5.1 Umbrella (revision 2.2.5.1-14-g05b653355c)
[000055953cf4c3b8] core libvlc debug: VLC media player - 2.2.5.1 Umbrella
[000055953cf4c3b8] core libvlc debug: Copyright © 1996-2017 the VideoLAN team
[000055953cf4c3b8] core libvlc debug: revision 2.2.5.1-14-g05b653355c
[000055953cf4c3b8] core libvlc debug: configured with ./configure 
'--disable-chromaprint'
[000055953cf4c3b8] core libvlc debug: searching plug-in modules
[000055953cf4c3b8] core libvlc debug: loading plugins cache file
/home/alfredo/vlc-2.2.5.1/src/.libs/vlc/plugins/plugins.dat
[000055953cf4c3b8] core libvlc warning: cannot read
/home/alfredo/vlc-2.2.5.1/src/.libs/vlc/plugins/plugins.dat: No such file
or directory
[000055953cf4c3b8] core libvlc debug: recursively browsing
`/home/alfredo/vlc-2.2.5.1/src/.libs/vlc/plugins'
[000055953cf4c3b8] core libvlc debug: saving plugins cache
/home/alfredo/vlc-2.2.5.1/src/.libs/vlc/plugins/plugins.dat
[000055953cf4c3b8] core libvlc debug: loading plugins cache file
/home/alfredo/vlc-2.2.5.1/modules/plugins.dat
[000055953cf4c3b8] core libvlc debug: recursively browsing
`/home/alfredo/vlc-2.2.5.1/modules'
[000055953cf4c3b8] core libvlc warning: cannot load module
`/home/alfredo/vlc-2.2.5.1/modules/misc/.libs/libgnutls_plugin.so'
(/home/alfredo/vlc-2.2.5.1/modules/misc/.libs/libgnutls_plugin.so:
undefined symbol: nettle_sha1_init)

How can I solve ?
regards
Francesco