emerge --backtrack=50 --verbose-conflicts -v dev-lang/python Local copy of remote index is up-to-date and will be used. Local copy of remote index is up-to-date and will be used. These are the packages that would be merged, in order: Calculating dependencies... done! [binary U ] sys-libs/gdbm-1.18.1:0/6::gentoo [1.13-r2:0/1.13::gentoo] USE="berkdb nls readline -static-libs (-exporter%)" ABI_X86="(64) -32 (-x32)" 258 KiB [binary NS ] dev-lang/python-3.8.5:3.8::gentoo [2.7.18:2.7::gentoo, 3.7.7-r2:3.7/3.7m::gentoo] USE="gdbm ipv6 ncurses readline sqlite ssl xml -bluetooth -build -examples -hardened -libressl -test -tk -wininst" 25439 KiB Total: 2 packages (1 upgrade, 1 in new slot, 2 binaries), Size of downloads: 25696 KiB !!! Multiple package instances within a single package slot have been pulled !!! into the dependency graph, resulting in a slot conflict: sys-libs/gdbm:0 (sys-libs/gdbm-1.18.1:0/6::gentoo, binary scheduled for merge) USE="berkdb nls readline -static-libs" ABI_X86="(64) -32 (-x32)" pulled in by sys-libs/gdbm:0/6=[berkdb] required by (dev-lang/python-3.8.5:3.8/3.8::gentoo, binary scheduled for merge) USE="gdbm ipv6 ncurses readline sqlite ssl xml -bluetooth -build -examples -hardened -libressl -test -tk -wininst" ABI_X86="(64)" ^^^^^ (sys-libs/gdbm-1.13-r2:0/1.13::gentoo, installed) USE="berkdb nls readline -exporter -static-libs" ABI_X86="(64) -32 (-x32)" pulled in by >=sys-libs/gdbm-1.8.3:0/1.13= required by (dev-lang/perl-5.30.3:0/5.30::gentoo, installed) USE="berkdb gdbm ithreads -debug -doc" ABI_X86="(64)" ^^^^^^^^ sys-libs/gdbm:0/1.13=[berkdb] required by (dev-lang/python-2.7.18:2.7/2.7::gentoo, installed) USE="gdbm ipv6 ncurses readline sqlite ssl (threads) (wide-unicode) xml (-berkdb) -bluetooth -build -examples -hardened -libressl -tk -wininst" ABI_X86="(64)" ^^^^^^^^ sys-libs/gdbm:0/1.13=[berkdb] required by (dev-lang/python-3.7.7-r2:3.7/3.7m::gentoo, installed) USE="gdbm ipv6 ncurses readline sqlite ssl xml -bluetooth -build -examples -hardened -libressl -test -tk -wininst" ABI_X86="(64)" ^^^^^^^^ sys-libs/gdbm:0/1.13= required by (sys-apps/man-db-2.8.7:0/0::gentoo, installed) USE="berkdb gdbm manpager seccomp zlib -nls (-selinux) -static-libs" ABI_X86="(64)" ^^^^^^^^ >=sys-libs/gdbm-1.10-r1:0/1.13=[abi_x86_64(-)] required by (dev-libs/cyrus-sasl-2.1.27-r3:2/2::gentoo, installed) USE="berkdb gdbm pam ssl -authdaemond -java -kerberos -ldapdb -libressl -mysql -openldap -postgres -sample (-selinux) -sqlite -srp -static-libs -urandom" ABI_X86="(64) -32 (-x32)" ^^^^^^^^ !!! The slot conflict(s) shown above involve package(s) which may need to !!! be rebuilt in order to solve the conflict(s). However, the following !!! package(s) cannot be rebuilt for the reason(s) shown: (sys-apps/man-db-2.8.7:0/0::gentoo, installed): ebuild is masked or unavailable (dev-lang/python-2.7.18:2.7/2.7::gentoo, installed): ebuild is masked or unavailable (dev-lang/python-3.7.7-r2:3.7/3.7m::gentoo, installed): ebuild is masked or unavailable 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. For more information, see MASKED PACKAGES section in the emerge man page or refer to the Gentoo Handbook. !!! The following installed packages are masked: - sys-libs/glibc-2.30-r8::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. For more information, see the MASKED PACKAGES section in the emerge man page or refer to the Gentoo Handbook.