Peaclock uses C++17, this requires us to go through some hoops.

sudo apt install clang-7 llvm-7-dev
git clone https://github.com/octobanana/peaclock.git
cd peaclock
export CC=/usr/bin/clang-7
export CXX=/usr/bin/clang++-7
find . -type f -exec sed -i -e \ 
's#std::filesystem#std::experimental::filesystem#g' {} \;
find . -type f -exec sed -i -e  \
's#<filesystem>#<experimental/filesystem>#g' {} \;
find . -type f -exec sed -i -e \
's/lexically_normal().//g' {} \; # HACK!
./build.sh
./install.sh