Installing BlueZ 5.50 doesn't update bluetoothd

Question

I'm trying to install BlueZ 5.50 on Ubuntu 16.04 because I need MIDI support.

I compiled and installed it as follows:

sudo apt-get install libudev-dev
sudo apt-get install libical-dev
sudo apt-get install libreadline-dev
cd bluez-5.50
./configure --enable-midi
make -j8
sudo make install

The problem is that it doesn't update /usr/sbin/bluetoothd, which is the default version that is started when I reboot.
bluetoothd -v results in 5.37
but ./src/bluetoothd -v results in 5.50.

The only version in the path seems to be the old version:

whereis bluetoothd
bluetoothd: /usr/sbin/bluetoothd /usr/share/man/man8/bluetoothd.8.gz

Why does the install script keep the old version? How can I update everything to the new version? Do I have to?

Right now, MIDI BLE seems to be working, even with the old version of bluetoothd.

Answer 1

If you compile a programm from sources and do not use pre-compiled dpkg packages, the dpkg packages will not be touched or changed in any way.

Normally, the configure step instructs the build to use /usr/local as install prefix, instead of /usr. This is to prevent self-compiled stuff to override binaries or other files that are shipped within a dpkg package.
So you bluetoothd binary resides somewhere in /usr/local.

root@localhost:~/bluez-5.50# find /usr/local -name bluetoothd
/usr/local/libexec/bluetooth/bluetoothd

Unfortunately or luckily, not really sure, the make install does place a systemd service and target in /lib/systemd/system, which overrides the files from the dpkg package bluez.
In my opinion, these two files should go into /etc/systemd/system to prevent e.g. an update of bluez overwriting your manually installed version. To make that, you also should add --with-systemdsystemunitdir=/etc/systemd/system to your configure command and reinstall the new bluez and the old bluez.

root@localhost:~/bluez-5.50# ./configure --enable-midi --with-systemdsystemunitdir=/etc/systemd/system
root@localhost:~/bluez-5.50# make 
root@localhost:~/bluez-5.50# make install
root@localhost:~/bluez-5.50# apt-get install --reinstal bluez