installation is slow
As already reported in the Gentoo tracker:
The problem is this block:
size='scalable-up-to-32'
for file in `cd ../../Adwaita/$size; find . -name "*.png"`; do \
context="`dirname $file`"; \
/bin/mkdir -p /var/tmp/portage/x11-themes/adwaita-icon-theme-3.32.0/image//usr/share/icons/Adwaita/$size/$context; \
/bin/sh /var/tmp/portage/x11-themes/adwaita-icon-theme-3.32.0/work/adwaita-icon-theme-3.32.0/install-sh -c -m 644 ../../Adwaita/$size/$file /var/tmp/portage/x11-themes/adwaita-icon-theme-3.32.0/image//usr/share/icons/Adwaita/$size/$file; \
done; \
for file in `cd ../../Adwaita/scalable-up-to-32; find . -name "*.svg"`; do \
context="`dirname $file`"; \
/bin/mkdir -p /var/tmp/portage/x11-themes/adwaita-icon-theme-3.32.0/image//usr/share/icons/Adwaita/scalable-up-to-32/$context; \
/bin/sh /var/tmp/portage/x11-themes/adwaita-icon-theme-3.32.0/work/adwaita-icon-theme-3.32.0/install-sh -c -m 644 ../../Adwaita/scalable-up-to-32/$file /var/tmp/portage/x11-themes/adwaita-icon-theme-3.32.0/image//usr/share/icons/Adwaita/scalable-up-to-32/$file; \
done
This installs files one by one, uses explicit mkdir and install-sh instead of plain "install" with "-D". This forks a gazillion of process, which takes minutes to complete. And it calls dirname for every file.