I tried to compile bluez for ubuntu 18.04 downloading the latest version (5.50) from here.
configure
command:
./configure --prefix=/usr --mandir=/usr/share/man --sysconfdir=/etc --localstatedir=/var --enable-mesh
Fails with the message:
...
checking for ELL... no
configure: error: ell library >= 0.3 is required
I ignore what is ELL and why it is used (nice to know), but the true question is about the missing dependencies to install for getting rid off this error.
I believe you need to install the Embedded Linux Library.
Might be the Microsoft Embedded Learning Library, but not as likely.