Hi John, On Sat, 21 Nov 2020 at 01:15, John Soo wrote: > I was curious how fast this gccemacs branch might be, so I got it to > compile. Thanks! This motivates me to resume what had been discussed here [1]: be able to somehow run: --8<---------------cut here---------------start------------->8--- guix build emacs-magit emacs-foo emacs-bar --with-input=emacs=gccemacs --8<---------------cut here---------------end--------------->8--- At least, have a package transformation that allow to rebuild all the Emacs packages with the ’gccemacs’ VM instead of the current Emacs 27 one. > It feels fast but there are bugs and the closure is huge. Also these > patches do not use any of the parameterization machinery. What do you mean by “parameterization machinery”? The new ’with-parameter’ introduced here [2] or the package transformation that replaces all the dependencies (explicit and implicit). 1: 2: All the best, simon