Colors and progress indicators on buildprocesses

[swedebugia]

Hi

I recently installed Parabola and have played around a bit with 
compiling AUR-packages to be able to run the programs I want - packaged 
or not.

Having build a lot on guixsd a while ago I noticed some differences in 
the cli-overview that I would like to present.

Colorfication and arrows (=>) are used to clearly distinguish 
pacaur/pacman-commands from the buildprocess output.

A nice thing I saw on some builds (build of qt during build of 
telegram-desktop) was a per build process percentage indicator located 
in the beginning of each line of build output like this:
[ 0% ] lorem ipsum....
[ 10% ] lorem ipsum....

In addition to these two above I have an idea as well:
Use the terminal-title wisely to show the progress of the whole 
transaction and the current running build (e.g.: "Download complete. 
Buildprogress 4/5: building qt"

What do you think?