Hi!

I wanted to add couple of ligatures to Fira Mono similar to what Hasklig does to Source Code Pro, for personal use.

I’m trying to build Fira Mono from sources but am completely lost. Can you describe what tools I need and short step-by-step explanation what to run in which order?

I’ve tried:

• opening Fira Mono-Regular.otf OTF version in FontLab studio but on save it cannot compile OTF features.
• running makeotf -f Fira\ Mono-Regular.ufo from AFDKO but it crashes.

I’m a total newbie with modern font editing and I just want to add couple of glyphs and ligature feature. Can you help me with this? (preferably without buying Glyphs.app which is kinda expensive for 1-time personal usage)

Thanks! (great font btw, use it everyday for code editing & in terminal)