libpulse-dev installation problem [duplicate]
"(phased 20%)"
see https://wiki.ubuntu.com/PhasedUpdates https://wiki.ubuntu.com/ErrorTracker/PhasedUpdates
You can wait until the phasing period is over (currently on 50%) or install the package providing the version numbers:
Either
sudo apt install libpulse-dev=1:15.0+dfsg1-1ubuntu2 libpulse0=1:15.0+dfsg1-1ubuntu2 libpulse-mainloop-glib0=1:15.0+dfsg1-1ubuntu2
or
sudo apt install libpulse-dev=1:15.0+dfsg1-1ubuntu2.2 libpulse0=1:15.0+dfsg1-1ubuntu2.2 libpulse-mainloop-glib0=1:15.0+dfsg1-1ubuntu2.2
This seems to be a specific case that may deserve a bug report on Launchpad see also https://answers.launchpad.net/ubuntu/+source/pulseaudio/+question/699828