Gentoo ~ # emerge --oneshot portage Calculating dependencies... done! [ebuild R ] app-portage/gemato-14.3 PYTHON_TARGETS="python3_7* -python3_6*" [ebuild U ] sys-apps/portage-2.3.99-r2 [2.3.89-r1] PYTHON_TARGETS="python3_7* -python3_6*" !!! Multiple package instances within a single package slot have been pulled !!! into the dependency graph, resulting in a slot conflict: sys-apps/portage:0 (sys-apps/portage-2.3.99-r2:0/0::gentoo, ebuild scheduled for merge) USE="(ipc) native-extensions rsync-verify (xattr) -apidoc -build -doc -gentoo-dev (-selinux)" ABI_X86="(64)" PYTHON_TARGETS="python3_7 (-pypy3) -python3_6 (-python3_8)" pulled in by sys-apps/portage (Argument) (sys-apps/portage-2.3.89-r1:0/0::gentoo, installed) USE="(ipc) native-extensions rsync-verify (xattr) -apidoc -build -doc -gentoo-dev (-selinux)" ABI_X86="(64)" PYTHON_TARGETS="python2_7 python3_6 (-pypy3) -python3_7 (-python3_8)" pulled in by >=sys-apps/portage-2.2.16[python_targets_python3_6(-),-python_single_target_python3_6(-)] required by (app-portage/layman-2.4.2-r1:0/0::gentoo, installed) USE="git gpg mercurial sync-plugin-portage -bazaar -cvs (-darcs) (-g-sorcery) -sqlite -squashfs -subversion -test" ABI_X86="(64)" PYTHON_TARGETS="python3_6" sys-apps/portage[python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (app-portage/gentoolkit-0.4.6:0/0::gentoo, installed) USE="" ABI_X86="(64)" PYTHON_TARGETS="python3_6 -python3_7" sys-apps/portage[python_targets_python3_6(-)?,python_targets_python3_7(-)?,python_targets_python3_8(-)?,-python_single_target_python3_6(-),-python_single_target_python3_7(-),-python_single_target_python3_8(-)] required by (dev-java/java-config-2.2.0-r4:2/2::gentoo, installed) USE="-test" ABI_X86="(64)" PYTHON_TARGETS="python3_6 -python3_7" sys-apps/portage[python_targets_python3_6(-)?,python_targets_python3_7(-)?,-python_single_target_python3_6(-),-python_single_target_python3_7(-)] required by (app-portage/pfl-3.0.1-r3:0/0::gentoo, installed) USE="network-cron" ABI_X86="(64)" PYTHON_TARGETS="python3_6 -python3_7" app-portage/gemato:0 (app-portage/gemato-14.3:0/0::gentoo, ebuild scheduled for merge) USE="gpg -test -tools" ABI_X86="(64)" PYTHON_TARGETS="python3_7 (-pypy3) -python3_6 (-python3_8)" pulled in by >=app-portage/gemato-14[python_targets_pypy3(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,python_targets_python3_8(-)?,-python_single_target_pypy3(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-),-python_single_target_python3_8(-)] required by (sys-apps/portage-2.3.99-r2:0/0::gentoo, ebuild scheduled for merge) USE="(ipc) native-extensions rsync-verify (xattr) -apidoc -build -doc -gentoo-dev (-selinux)" ABI_X86="(64)" PYTHON_TARGETS="python3_7 (-pypy3) -python3_6 (-python3_8)" (app-portage/gemato-14.3:0/0::gentoo, installed) USE="blake2 bzip2 gpg -lzma -sha3 -test -tools" ABI_X86="(64)" PYTHON_TARGETS="python2_7 python3_6 (-pypy3) -python3_7 (-python3_8)" pulled in by >=app-portage/gemato-14[python_targets_python2_7(-),python_targets_python3_6(-),-python_single_target_pypy3(-),-python_single_target_python2_7(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-),-python_single_target_python3_8(-)] required by (sys-apps/portage-2.3.89-r1:0/0::gentoo, installed) USE="(ipc) native-extensions rsync-verify (xattr) -apidoc -build -doc -gentoo-dev (-selinux)" ABI_X86="(64)" PYTHON_TARGETS="python2_7 python3_6 (-pypy3) -python3_7 (-python3_8)" It may be possible to solve this problem by using package.mask to prevent one of those packages from being selected. However, it is also possible that conflicting dependencies exist such that they are impossible to satisfy simultaneously. If such a conflict exists in the dependencies of two different packages, then those packages can not be installed simultaneously. You may want to try a larger value of the --backtrack option, such as --backtrack=30, in order to see if that will solve this conflict automatically. For more information, see MASKED PACKAGES section in the emerge man page or refer to the Gentoo Handbook. !!! The following installed packages are masked: - dev-java/icedtea-web-1.6.2::gentoo (masked by: package.mask) /usr/portage/profiles/package.mask: # Georgy Yakovlev (2020-03-27) # Vulnerable old version of icedtea-web #711392 # new version is not packaged yet # package is not going away anytime soon, just masked # for security. unmask as needed. - sys-libs/glibc-2.29-r7::gentoo (masked by: package.mask) /usr/portage/profiles/package.mask: # Michał Górny , Andreas K. Hüttel , # Matthias Maier (2017-05-21 and later updates) # These old versions of toolchain packages (binutils, gcc, glibc) are no # longer officially supported and are not suitable for general use. Using # these packages can result in build failures (and possible breakage) for # many packages, and may leave your system vulnerable to known security # exploits. # If you still use one of these old toolchain packages, please upgrade (and # switch the compiler / the binutils) ASAP. If you need them for a specific # (isolated) use case, feel free to unmask them on your system. - x11-libs/libXxf86misc-1.0.4::gentoo (masked by: package.mask) /usr/portage/profiles/package.mask: # Matt Turner (2020-05-08) # Client-side library for an X extension that has not been supported by Xorg # for about a decade. Masked for removal in 30 days. Bug #720150 For more information, see the MASKED PACKAGES section in the emerge man page or refer to the Gentoo Handbook.