Spacemacs: use font ligatures?

[c0c0n3]

The unicode fonts layer makes the unicode font experience better and also adds support for ligatures through mickeynp's package. But notice mickeynp warns about using Emacs 27 (current release) since there's a bug that causes nasty crashes when using the ligatures package. The bug got fixed in Emacs dev and will be part of the upcoming Emacs 28 release.

• Use ligatures when Emacs 28 gets released?
• Ditch Source Code Pro as default and use Cascadia instead?

Refs:

• https://develop.spacemacs.org/layers/+fonts/unicode-fonts/README.html
• https://github.com/mickeynp/ligature.el

[c0c0n3]

Notice there's another issue w/ OTF font weights. Many fonts like Cascadia support several weights, like extra-light, that aren't picked up by Emacs. For example, I tried this in my Spacemacs config

dotspacemacs-default-font (spacefont
                               '("Cascadia Code"
                                :size 19
                                :weight extra-light
                                :width normal))

to replace Source Code Pro (size: 18, weight: light) w/ a Cascadia font spec that should be as close a possible in terms of size and weight. But Emacs selects Cascadia w/ a weight of normal, even though I do have the extra light variant installed. Apparently this is a bug that's been fixed in Emacs 28:

• https://emacs.stackexchange.com/questions/32377
• http://git.savannah.gnu.org/cgit/emacs.git/commit/src/font.c?id=65fd3ca84f75aee0dfebb87fa793dae57c1caf35

So another more reason to wait until Emacs 28 gets released.