Simply typing

    make install

should install passage to the standard locations.

To install on a macOS system with Homebrew type

    make install PREFIX="$(brew --cellar)/passage/$(git describe --tags)"
    brew link passage

The makefile is aware of the following environment variables:

PREFIX      default: /usr
DESTDIR     default: 
BINDIR      default: $(PREFIX)/bin
LIBDIR      default: $(PREFIX)/lib

-- Completion Files --

The install target will automatically determine the existance
of bash, zsh, and fish, and install the completion files as
needed. If you'd like to choose manually, you may set WITH_ALLCOMP,
WITH_BASHCOMP, WITH_ZSHCOMP, or WITH_FISHCOMP to "yes" or "no". The
exact paths of the completions can be controlled with BASHCOMPDIR,
ZSHCOMPDIR, and FISHCOMPDIR.
