[RESOLVED] USE with qt4 and X

Hello. I am French and use Google traduction for my bad english.
My previous message asking for information about installing HPLIP and it worked well, thank you. During this installation I got the following message: “you need USE = qt4 for the hplip GUI and also you need USE = X for the scanner gui”. I figured that if I used USE well, I have a GUI for HPLIP and scanner. I understand for HPLIP but little for the scanner since I use Xsane. I created a file etc / make.conf that I had not and set USE = “qt4 X”. Then I used emerge -uN world that I posted this result :

emerge uN world
Found 2 make.conf files, using both '/etc/make.conf' and '/etc/portage/make.conf'
Calculating dependencies /
Problem resolving dependencies for www-client/qupzilla from @selected
... done!
he ebuild selected to satisfy "www-client/qupzilla" has unmet requirements.
www-client/qupzilla-1.8.9-r3::calculate USE="dbus qt4 qt5 -debug -gnome-keyring -kde -nonblockdialogs" LINGUAS="bg_BG cs_CZ de_DE es_ES es_VE fi_FI fr_FR hr_HR hu_HU it_IT lv_LV nl_NL pl_PL pt_BR pt_PT ro_RO ru_RU sk_SK sr sv_SE uk_UA -ar_SA -ca_ES -el_GR -es_MX -eu_ES -fa_IR -gl_ES -he_IL -id_ID -ja_JP -ka_GE -lg -nqo -sr@ijekavian -sr@ijekavianlatin -sr@latin -tr_TR -uz@Latn -zh_CN -zh_TW" 
The following REQUIRED_USE flag constraints are unsatisfied:
exactly-one-of ( qt4 qt5 )
The above constraints are a subset of the following complete expression:
exactly-one-of ( qt4 qt5 ) kde? ( qt4 )
(dependency required by "@selected" [set])
(dependency required by "@world" [argument])

Must we choose between qt4 and qt5 ? I do not know what to do. Thank you.

Try to use the qt4 and X flags only for net-print/hplip package. For this append the line to /etc/portage/package.use/custom

net-print/hplip X qt4

Thank you. This worked well and I selected “HP Device Manager”. My printer and scanner are created and functioning.