Missing a link against libX11 in Linux.

[lepalom]

Preparing a new version of the package of Coin3 I have found a strange message:

dpkg-shlibdeps: warning: symbol XFree used by debian/libcoin80c/usr/lib/x86_64-linux-gnu/libCoin.so.4.0.0 found in none of the libraries
dpkg-shlibdeps: warning: symbol XFreePixmap used by debian/libcoin80c/usr/lib/x86_64-linux-gnu/libCoin.so.4.0.0 found in none of the libraries
dpkg-shlibdeps: warning: symbol XScreenNumberOfScreen used by debian/libcoin80c/usr/lib/x86_64-linux-gnu/libCoin.so.4.0.0 found in none of the libraries
dpkg-shlibdeps: warning: symbol XCreatePixmap used by debian/libcoin80c/usr/lib/x86_64-linux-gnu/libCoin.so.4.0.0 found in none of the libraries
dpkg-shlibdeps: warning: symbol XCloseDisplay used by debian/libcoin80c/usr/lib/x86_64-linux-gnu/libCoin.so.4.0.0 found in none of the libraries
dpkg-shlibdeps: warning: symbol XOpenDisplay used by debian/libcoin80c/usr/lib/x86_64-linux-gnu/libCoin.so.4.0.0 found in none of the libraries
dpkg-shlibdeps: warning: symbol XDefaultScreenOfDisplay used by debian/libcoin80c/usr/lib/x86_64-linux-gnu/libCoin.so.4.

Checking CMakelist.txt, I have found that only is activated if COIN_BUILD_MAC_X11 is on, but in GNU/Linux it is off: it is not MAC.

Before I begin to patch Coin3, I would like to ask here if this is correct or not. From my point of view, in GNU/Linux platforms you have to add a link flag against libX11.