# emerge -avuND --with-bdeps=y --complete-graph=y --backtrack=30 --keep-going --verbose-conflicts --exclude gentoo-sources --exclude firefox --exclude libreoffice --exclude chromium --exclude glibc --exclude gcc world

These are the packages that would be merged, in order:

Calculating dependencies... done!   
[ebuild     U  ] dev-libs/vala-common-0.36.4::dantrell-gnome [0.36.3::dantrell-gnome] 2780 KiB
[ebuild   R    ] app-admin/eselect-1.4.9::dantrell-gnome  USE="multischema* -doc -emacs -vim-syntax" 0 KiB
[ebuild   R    ] dev-lang/python-3.4.5:3.4/3.4m::gentoo  USE="gdbm ipv6 ncurses readline ssl (threads) xml -build -examples -hardened (-libressl) -sqlite* -tk -wininst" 0 KiB
[ebuild   R    ] net-misc/curl-7.53.0::gentoo  USE="ipv6 ldap ssl -adns -http2 -idn -kerberos -metalink -rtmp -samba -ssh -static-libs {-test} -threads" CURL_SSL="openssl -axtls -gnutls (-libressl) -mbedtls -nss (-winssl) (-polarssl%)" 0 KiB
[ebuild   R    ] net-misc/rsync-3.1.2::gentoo  USE="acl iconv ipv6 xattr -examples% -static -stunnel" 872 KiB
[ebuild     U  ] media-libs/mesa-17.0.6::gentoo [13.0.5::gentoo] USE="bindist classic dri3 egl gallium gbm llvm nptl -d3d9 -debug -gles1 -gles2 -opencl -openmax -osmesa -pax_kernel -pic (-selinux) -vaapi -valgrind -vdpau -vulkan -wayland -xa -xvmc (-gcrypt%) (-libressl%) (-nettle%*) (-openssl%)" VIDEO_CARDS="intel nouveau radeon radeonsi (-freedreno) -i915 -i965 -imx% -r100 -r200 -r300 -r600 (-vc4) (-vivante) -vmware" 0 KiB
[ebuild     U  ] media-libs/libepoxy-1.4.2::gentoo [1.4.1::gentoo] USE="X {-test}" 0 KiB
[ebuild     UD ] dev-util/gdbus-codegen-2.50.3::dantrell-gnome [2.52.2::dantrell-gnome] PYTHON_TARGETS="python2_7 python3_4 (-python3_5) (-python3_6)" 0 KiB
[ebuild  r  U  ] x11-base/xorg-server-1.19.3:0/1.19.3::gentoo [1.19.2:0/1.19.2::gentoo] USE="glamor ipv6 suid udev xorg -debug -dmx -doc -kdrive (-libressl) -minimal (-selinux) -static-libs -systemd -tslib -unwind -wayland -xephyr -xnest -xvfb" 0 KiB
[ebuild  rR    ] x11-drivers/xf86-video-fbdev-0.4.4::gentoo  0 KiB
[ebuild  rR    ] x11-drivers/xf86-video-vesa-2.3.4::gentoo  0 KiB
[ebuild  rR    ] x11-drivers/xf86-video-dummy-0.3.8::gentoo  USE="-dga" 0 KiB
[ebuild  rR    ] x11-drivers/xf86-input-mouse-1.9.2::gentoo  0 KiB
[ebuild  rR    ] x11-drivers/xf86-input-keyboard-1.9.0::gentoo  0 KiB
[ebuild     U  ] x11-drivers/xf86-input-libinput-0.25.1::gentoo [0.24.0::gentoo] 0 KiB
[ebuild     U  ] x11-drivers/xf86-video-amdgpu-1.3.0::gentoo [1.2.0::gentoo] USE="glamor" 0 KiB
[ebuild     U  ] x11-drivers/xf86-video-nouveau-1.0.15::gentoo [1.0.13::gentoo] 0 KiB
[ebuild     U  ] x11-drivers/xf86-video-ati-7.9.0::gentoo [7.8.0::gentoo] USE="glamor udev" 0 KiB
[ebuild     U  ] x11-drivers/xf86-video-intel-2.99.917_p20170313::gentoo [2.99.917_p20170216::gentoo] USE="dri sna udev -debug -dri3 -tools -uxa -xvmc" 0 KiB
[ebuild  r  UD ] dev-libs/glib-2.50.3-r1:2/50::dantrell-gnome [2.52.2:2/52::dantrell-gnome] USE="dbus (mime) xattr -debug (-fam) (-selinux) -static-libs -systemtap {-test} -utils" PYTHON_TARGETS="python2_7" 0 KiB
[blocks b      ] <dev-util/gdbus-codegen-2.52.2 ("<dev-util/gdbus-codegen-2.52.2" is blocking dev-libs/glib-2.52.2)
[ebuild   R    ] app-accessibility/at-spi2-core-2.22.1:2::dantrell-gnome-3-22 [2.22.1:2::gentoo] USE="X introspection" 0 KiB
[ebuild   R    ] gnome-base/dconf-0.26.0-r1::dantrell-gnome [0.26.0-r1::gentoo] USE="{-test}" 0 KiB
[ebuild  rR    ] dev-libs/libgudev-230-r1::gentoo  USE="introspection -static-libs" 0 KiB
[ebuild  r  U  ] app-text/poppler-0.54.0:0/67::dantrell-gnome [0.45.0:0/62::gentoo] USE="cairo cxx introspection jpeg jpeg2k lcms png tiff utils -cjk -curl -debug -doc -nss -qt4* -qt5 (-cairo-qt%)" 0 KiB
[ebuild   R    ] app-accessibility/at-spi2-atk-2.22.0:2::dantrell-gnome-3-22 [2.22.0:2::gentoo] USE="{-test}" 0 KiB
[ebuild     U  ] x11-libs/pango-1.40.6::dantrell-gnome [1.40.5::gentoo] USE="X introspection {-test}" 0 KiB
[ebuild   R    ] gnome-base/librsvg-2.40.17:2::dantrell-gnome [2.40.17:2::gentoo] USE="introspection -tools -vala" 0 KiB
[ebuild     U  ] x11-themes/adwaita-icon-theme-3.22.0-r2::dantrell-gnome-3-22 [3.22.0-r1::gentoo] USE="branding" 0 KiB
[ebuild   R    ] x11-wm/openbox-3.6.1:3::gentoo  USE="branding imlib* nls session startup-notification svg -debug -static-libs -xdg" PYTHON_TARGETS="python2_7" 0 KiB
[ebuild  r  U  ] x11-libs/gtk+-3.22.16:3/22::dantrell-gnome [3.22.12:3/3::gentoo] USE="X cups introspection (-aqua) -broadway -cloudprint -colord -examples {-test} -vim-syntax -wayland -xinerama" 18218 KiB
[ebuild  rR    ] net-print/cups-filters-1.12.0::dantrell-gnome  USE="dbus foomatic jpeg ldap pdf png postscript tiff -perl -static-libs -zeroconf" 0 KiB
[ebuild   R    ] x11-libs/gtk+-2.24.31-r1:2::dantrell-gnome [2.24.31-r1:2::gentoo] USE="cups introspection (-aqua) -examples {-test} -vim-syntax -xinerama" 0 KiB
[ebuild  rR    ] xfce-base/libxfce4ui-4.13.0::gentoo  USE="startup-notification -debug -glade" 0 KiB
[ebuild   R    ] x11-themes/gtk-engines-adwaita-3.22.3::dantrell-gnome [3.22.3::gentoo] 0 KiB
[ebuild   R    ] sys-apps/lshw-02.16b-r2::gentoo  USE="gtk* -sqlite -static" 0 KiB
[ebuild  rR    ] xfce-base/exo-0.10.7::gentoo  USE="-debug" 0 KiB
[ebuild  rR    ] xfce-base/garcon-0.5.0-r2::gentoo  USE="-debug" 0 KiB
[ebuild  rR    ] xfce-base/xfwm4-4.12.3-r1::gentoo  USE="dri startup-notification xcomposite -debug" 0 KiB
[ebuild  rR    ] xfce-base/xfce4-appfinder-4.12.0-r1::gentoo  USE="-debug" 0 KiB
[ebuild   R    ] dev-qt/qtcore-4.8.7-r2:4::gentoo  USE="exceptions glib iconv qt3support* ssl (-aqua) -debug -icu (-libressl) -pch" 0 KiB
[ebuild     U  ] dev-qt/qtgui-4.8.7:4::gentoo [4.8.6-r4:4::gentoo] USE="accessibility cups exceptions glib mng qt3support tiff xv (-aqua) -debug -egl -gtkstyle -nas -nis -pch -trace -xinerama" 0 KiB
[ebuild     U  ] dev-qt/qtsql-4.8.7-r1:4::gentoo [4.8.6-r1:4::gentoo] USE="exceptions qt3support sqlite (-aqua) -debug -freetds -mysql -oci8 -odbc -pch -postgres" 0 KiB
[ebuild     U  ] dev-qt/qt3support-4.8.7:4::gentoo [4.8.6-r1:4::gentoo] USE="accessibility exceptions (-aqua) -debug -pch" 0 KiB
[ebuild   R    ] app-crypt/pinentry-0.9.7-r1::dantrell-gnome [0.9.7-r1::gentoo] USE="gtk ncurses qt4 -caps -emacs -gnome-keyring -qt5 -static" 0 KiB
[ebuild     U  ] app-crypt/gnupg-2.1.21-r1::dantrell-gnome [2.1.21::dantrell-gnome] USE="bzip2 gnutls ldap nls readline smartcard usb -doc (-selinux) -tofu -tools -wks-server" 0 KiB
[ebuild     U  ] sys-auth/pambase-20150213-r1::dantrell-gnome [20150213::gentoo] USE="consolekit cracklib nullok sha512 -debug (-elogind) -gnome-keyring -minimal -mktemp -pam_krb5 -pam_ssh -passwdqc -securetty (-selinux) -systemd" 0 KiB
[ebuild     U  ] net-misc/openssh-7.5_p1-r1::gentoo [7.3_p1-r7::gentoo] USE="X bindist hpn ldap pam pie ssl -X509 -audit% -debug -kerberos -ldns -libedit (-libressl) -livecd -sctp (-selinux) -skey -ssh1 -static {-test}" 0 KiB
[ebuild     U  ] app-admin/sudo-1.8.20_p2::gentoo [1.8.18_p1::gentoo] USE="ldap nls pam sendmail -gcrypt% -offensive -openssl% (-selinux) -skey" 0 KiB
[ebuild     UD ] sys-auth/consolekit-0.4.6::dantrell-gnome [1.1.0-r1::gentoo] USE="acl pam policykit -debug -doc (-selinux) -systemd-units% {-test} (-cgroups%) (-pm-utils%)" 370 KiB
[ebuild  rR    ] xfce-base/thunar-1.6.10-r1::gentoo  USE="dbus exif libnotify pcre udisks -debug {-test}" XFCE_PLUGINS="trash" 0 KiB
[ebuild  rR    ] xfce-base/xfdesktop-4.12.3::gentoo  USE="libnotify thunar -debug" 0 KiB
[ebuild     U  ] sys-apps/openrc-0.26.3::gentoo [0.24.2::gentoo] USE="ncurses netifrc pam unicode -audit -debug -newnet (-prefix) (-selinux) -static-libs" 0 KiB

Total: 52 packages (21 upgrades, 3 downgrades, 28 reinstalls), Size of downloads: 22240 KiB
Conflict: 1 block

WARNING: One or more updates/rebuilds have been skipped due to a dependency conflict:

dev-lang/python:2.7

  (dev-lang/python-2.7.12:2.7/2.7::gentoo, ebuild scheduled for merge) conflicts with
    >=dev-lang/python-2.7.5-r2:2.7[ncurses,sqlite,ssl,threads] required by (www-client/firefox-52.2.0:0/0::gentoo, installed)
                                           ^^^^^^             


The following packages are causing rebuilds:

  (dev-libs/glib-2.50.3-r1:2/50::dantrell-gnome, ebuild scheduled for merge) causes rebuilds for:
    (xfce-base/xfdesktop-4.12.3:0/0::gentoo, ebuild scheduled for merge)
    (xfce-base/libxfce4ui-4.13.0:0/0::gentoo, ebuild scheduled for merge)
    (dev-libs/libgudev-230-r1:0/0::gentoo, ebuild scheduled for merge)
    (xfce-base/xfce4-appfinder-4.12.0-r1:0/0::gentoo, ebuild scheduled for merge)
    (xfce-base/xfwm4-4.12.3-r1:0/0::gentoo, ebuild scheduled for merge)
    (xfce-base/garcon-0.5.0-r2:0/0::gentoo, ebuild scheduled for merge)
    (xfce-base/thunar-1.6.10-r1:0/0::gentoo, ebuild scheduled for merge)
    (xfce-base/exo-0.10.7:0/0::gentoo, ebuild scheduled for merge)
  (x11-libs/gtk+-3.22.16:3/22::dantrell-gnome, ebuild scheduled for merge) causes rebuilds for:
    (xfce-base/libxfce4ui-4.13.0:0/0::gentoo, ebuild scheduled for merge)
    (xfce-base/xfce4-appfinder-4.12.0-r1:0/0::gentoo, ebuild scheduled for merge)
    (xfce-base/garcon-0.5.0-r2:0/0::gentoo, ebuild scheduled for merge)
  (x11-base/xorg-server-1.19.3:0/1.19.3::gentoo, ebuild scheduled for merge) causes rebuilds for:
    (x11-drivers/xf86-video-dummy-0.3.8:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-video-vesa-2.3.4:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-video-intel-2.99.917_p20170313:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-input-libinput-0.25.1:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-input-mouse-1.9.2:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-input-keyboard-1.9.0:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-video-ati-7.9.0:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-video-nouveau-1.0.15:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-video-fbdev-0.4.4:0/0::gentoo, ebuild scheduled for merge)
    (x11-drivers/xf86-video-amdgpu-1.3.0:0/0::gentoo, ebuild scheduled for merge)
  (app-text/poppler-0.54.0:0/67::dantrell-gnome, ebuild scheduled for merge) causes rebuilds for:
    (net-print/cups-filters-1.12.0:0/0::dantrell-gnome, ebuild scheduled for merge)

Would you like to merge these packages? [Yes/No]