Global USE flag

Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see

Packages describing “debug” as local USE flag

Package “debug” Flag Description
app-admin/clsync Enable extra debugging. This will hurt performance badly. Be ready for tons of output.
app-arch/innoextract Enable debug logging and the --debug command-line option
app-cdr/dvdisaster Enable memory debugging.
app-editors/nano Enable debug messages and assert warnings. Note that these will all be sent straight to stderr rather than some logging facility.
app-i18n/librime Enable debugging (including logging of input of RIME input methods)
app-misc/rlwrap Enable debug
app-portage/eix Build with upstream's CXXFLAGS/LDFLAGS for debugging support; not recommended for normal use.
dev-haskell/warp Add additional debuging information
dev-java/jfreesvg Enable debugging during compilation.
dev-lang/crystal Build each module as a separate object file. Speeds build up.
dev-lang/spidermonkey Enable assertions to allow for easier debugging of programs that link to spidermonkey -- note this will often crash software on regular end-user systems
dev-libs/boost Build and install only the debug version of the Boost libraries. Only enable this flag if you're developing against boost.
dev-libs/libclsync Enable extra debugging. This will hurt performance badly. Be ready for tons of output.
dev-libs/libevent Support runtime debug mode and malloc hooks (for programmers)
dev-libs/libisofs Enable verbose debug messages
dev-libs/openct Add debug output to the driver library for pcsc-lite.
dev-perl/perl-headers Add source locations in generated .ph files to assist with debugging when errors occur
dev-scheme/guile Include malloc debugging code
dev-tcltk/expect-lite pull in packages needed for runtime interactive debugger
dev-util/google-perftools Build a set of libraries with debug support (so-called debugalloc). These are available by default but are not needed unless you're actually developing using tcmalloc.
games-board/teg Turn on debugging
games-emulation/zsnes Enable the builtin debugger
games-rpg/arx-libertatis Enable asserts and debug logging.
mail-filter/dspam Enable debugging support (don't enable this unless something needs testing!)
media-tv/mythtv Instructs Qt to use the 'debug' target
net-libs/tox Log level: 4
net-mail/vchkuser Enables debug messages to syslog
net-misc/ntpclient Enable analysis code path and debugging of NTP protocol.
net-misc/ptpd Enable debugging informations
net-misc/stargazer Enable extra debug codepaths, like asserts and extra output.
net-vpn/pptpd Log all GRE accepted packets when in debug mode (required if you want upstream support)
net-vpn/wireguard-modules Enable verbose debug reporting in dmesg of various WireGuard peer and device information.
net-wireless/spectools Build the raw output client for spectools. (for developers)
sci-libs/dealii Build an additional debug library with extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see <>
sys-apps/timer_entropyd Enable printf debugging and logging to the syslog at DEBUG level
sys-auth/pam_u2f Enable debug messages using the pam logging macros.
sys-auth/pambase Enable debug information logging on syslog(3) for all the modules supporting this in the system authentication and system login stacks.
sys-block/parted Enable debugging as encouraged by upstream: [The default configuration] includes --enable-debug (by default), which contains many assertions. Obviously, these "waste" space, but in the past, they have caught potentially dangerous bugs before they would have done damage, so we think it's worth it. Also, it means we get more bug reports ;)
sys-kernel/dracut Module installing additional tools like strace, file editor, ssh and more
sys-libs/glibc When USE=hardened, allow fortify/stack violations to dump core (SIGABRT) and not kill self (SIGKILL)
sys-libs/libunwind Adds support for DWARF .debug_frame section: Use the information from this section if available
sys-process/fcron Enable debug code and output. Since version 3.0.5 this will no longer force foreground execution, and fcron will be able to run as a service properly.
www-servers/monkeyd Enable lots of debugging info
x11-wm/e16 Build libtrip debugging library

All packages providing a “debug” USE flag (1561)