farout ~ # equery u mariadb
[ Legend : U - final flag setting for installation]
[        : I - package is installed with flag     ]
[ Colors : set, unset                             ]
 * Found these USE flags for dev-db/mariadb-10.2.14:
 U I
 + + backup          : <unknown>
 - - bindist         : Flag to enable or disable options for prebuilt (GRP) packages (eg. due to licensing issues)
 - - client-libs     : <unknown>
 + + cracklib        : Support for cracklib strong password checking
 - - debug           : Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful
                       backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
 + + extraengine     : <unknown>
 - - galera          : <unknown>
 - - innodb-lz4      : <unknown>
 - - innodb-lzo      : <unknown>
 - - innodb-snappy   : <unknown>
 - - jdbc            : <unknown>
 - - jemalloc        : <unknown>
 - - kerberos        : Add kerberos support
 - - latin1          : <unknown>
 - - libressl        : Use dev-libs/libressl as SSL provider (might need ssl USE flag), packages should not depend on
                       this USE flag
 - - mroonga         : <unknown>
 - - numa            : <unknown>
 - - odbc            : Add ODBC Support (Open DataBase Connectivity)
 - - oqgraph         : <unknown>
 - - pam             : Add support for PAM (Pluggable Authentication Modules) - DANGEROUS to arbitrarily flip
 + + perl            : Add optional support/bindings for the Perl language
 - - profiling       : <unknown>
 - - rocksdb         : <unknown>
 + + server          : <unknown>
 - - sphinx          : <unknown>
 - - sst-mariabackup : <unknown>
 - - sst-rsync       : <unknown>
 - - sst-xtrabackup  : <unknown>
 - - static          : !!do not set this during bootstrap!! Causes binaries to be statically linked instead of
                       dynamically
 - - static-libs     : Build static versions of dynamic libraries as well
 - - systemd         : Enable use of systemd-specific libraries and features like socket activation or session tracking
 - - systemtap       : <unknown>
 - - tcmalloc        : Use the dev-util/google-perftools libraries to replace the malloc() implementation with a possibly
                       faster one
 - - test            : Workaround to pull in packages needed to run with FEATURES=test. Portage-2.1.2 handles this
                       internally, so don't set it in make.conf/package.use anymore
 - - tokudb          : <unknown>
 + + xml             : Add support for XML files
 - - yassl           : <unknown>