Folk is built on Tcl, so you'll need to install the latest version for 'folk' to work correctly. MacOS has a version of tcl-tk installed by default but you really shouldn't use it because it's riddled with bugs and warnings. Let's get you set up with the latest version of Tcl ^{(as of June 2025)}:

1. Download the latest tcl-tk from Homebrew:

   • # In your terminal:
     /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
     # and then run this:
     brew install tcl-tk

2. Set your TCL_LIBRARY and TCLLIBPATH variables in your .bashrc, .zshrc, or similar:

   • # in your .bashrc, .zshrc, etc.:
     export PATH="/opt/homebrew/bin:$PATH"
     export TCL_LIBRARY="/opt/homebrew/lib/tcl8.6"
     export TCLLIBPATH="/opt/homebrew/lib"

3. Restart your terminal or source you config file, e.g. source .zshrc
4. Test that you've installed tclsh8.6 correctly on MacOS by running this:

   • # In your command line run:
     echo 'puts $tcl_version;exit 0' | tclsh
     9.0
     # ↑ Expected output, 9.0 or higher

5. TODO …