Thanks!
Just tried compiling entire darktable once more and I do get /opt/darktable/libexec/darktable/tools/darktable-noiseprofile.
Then what is
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX=/opt/darktable -DBUILD_NOISE_TOOLS=ON ..
cd tools/noise
make
sudo make install
for? If compiling tools only, shouldn’t cd tools/noise be the first line?