gentoo install root (disable cintex+reflex)

Something is wrong with compiling root5.20.00 on gentoo
(see this bug report)

add in /etc/portage/package.keywords

sci-physics/root ~x86

Then following this link
gerbaudo-hp ~ # ls /usr/portage/sci-physics/root/
ChangeLog files root-3.05.04.ebuild root-5.18.00d.ebuild root-5.20.00.ebuild
Manifest metadata.xml root-5.16.00.ebuild root-5.20.00-r1.ebuild
gerbaudo-hp ~ # mkdir /usr/local/portage
gerbaudo-hp ~ # mkdir /usr/local/portage/sci-physics
gerbaudo-hp ~ # mkdir /usr/local/portage/sci-physics/root
gerbaudo-hp ~ # cp /usr/portage/sci-physics/root/root-5.20.00.ebuild /usr/local/portage/sci-physics/root/
gerbaudo-hp ~ # cp -rp /usr/portage/sci-physics/root/files /usr/local/portage/sci-physics/root/

add one line in make .conf

gerbaudo-hp ~ # emacs -nw /etc/make.conf
gerbaudo-hp ~ # diff /etc/make.conf /etc/make.conf~
< PORTDIR_OVERLAY="/usr/local/portage"

gerbaudo-hp ~ # cd /usr/local/portage/sci-physics/root/

disable cintex and reflex from the ebuild

gerbaudo-hp root # emacs -nw root-5.20.00.ebuild
gerbaudo-hp root # diff root-5.20.00.ebuild root-5.20.00.ebuild~
142c142
< --disable-cintex \ --- > --enable-cintex \
148c148
< --disable-reflex \ --- > --enable-reflex \

and finally digest

gerbaudo-hp root # ebuild root-5.20.00.ebuild digest

Then

gerbaudo-hp root # emerge -av =root-5.20.00