Install dependencies:

sudo apt install build-essential pkg-config libxcb1-dev libxcb-util-dev libxcb-randr0-dev libxcb-keysyms1-dev libxcb-icccm4-dev libxcb-xinput-dev libxcb-xtest0-dev libfontconfig1-dev libxft-dev libxcursor-dev libbsd-dev libx11-xcb-dev 

Clone project:

git clone https://github.com/conformal/spectrwm
cd spectrwm/linux

Build and Install:

make
sudo make install

Verify Installation:

spectrwm -v

Use this command in the terminal:

yay -S spectrwm

As some configuration in Arch Linux has changed recently edit your local .spectrwm.conf file to set bar_font like this:

bar_font = xos4 Terminus:pixelsize=14:antialias=true

(Here assuming that font Terminus is installed. Other fonts that are listed with fc-list should also work)

For more details see also issue #193

Install using:

apt-get install spectrwm

Add these lines to your /etc/nixos/configuration.nix file:

# Enable the X11 window system (in case you don't have this already)
services.xserver.enable = true;

# Enable spectrwm tiling window manager
services.xserver.windowManager.spectrwm.enable = true;

pkgin in spectrwm

The example spectrwm.conf can be found at /usr/pkg/share/examples/spectrwm/spectrwm.conf.

Please see here