It should be possible to build pulseviz even if GTest is not installed.

[pckbls]

Lacking the latter should only result in not being able to build and execute the tests. This should not affect the build process of the pulseviz binary itself.

[dagelf]

Even so, here are instructions to install GTest

sudo apt install libgtest-dev build-essential cmake
cd /usr/src/googletest
sudo cmake .
sudo cmake --build . --target install