Global USE flags

Flag	Description	Packages
caps		2
cet	Enable Intel Control-flow Enforcement Technology.	2
clang	Allow building with clang (if proper environment is set). Highly experimental. Disable to auto-force gcc usage.	2
crypt	build and install libcrypt and crypt.h	2
debug	When USE=hardened, allow fortify/stack violations to dump core (SIGABRT) and not kill self (SIGKILL)	3
doc	Build documentation and man pages. With this USE flag disabled, the --help parameter for perf and its sub-tools will not be available. This is optional because it depends on a few documentation handling tools that are not always welcome on user systems.	4
hardened		2
perl	Add support for Perl as a scripting language for perf tools.	2
static-libs		2
systemtap	Add support to define SDT event in perf tools.	2
test		5
vanilla		2
xxhash	Enable <pkg>dev-libs/xxhash</pkg> support for hashing	2
zstd		2

Local USE flags

app-crypt

tomb

Flag	Description
gui
tray	Add a Tomb tray icon in a Qt desktop toolbar

dev-util

perf

Flag	Description
abi_mips_n32
abi_mips_n64
abi_mips_o32
babeltrace	Enable <pkg>dev-util/babeltrace</pkg> support
big-endian
bpf	Enable support for eBPF features with <pkg>dev-libs/libbpf</pkg>
capstone	Use <pkg>dev-libs/capstone</pkg> for disassembly support
gtk
java
libpfm	Enable <pkg>dev-libs/libpfm</pkg> support
libtraceevent	Enable <pkg>dev-libs/libtraceevent</pkg> support
libtracefs	Enable <pkg>dev-libs/libtracefs</pkg> support
lzma
numa	Enable NUMA support using <pkg>sys-process/numactl</pkg> (NUMA kernel support is also required)
python
slang
tcmalloc
unwind	Use <pkg>sys-libs/libunwind</pkg> for frame unwinding support.

net-misc

rsync

Flag	Description
acl
examples
iconv
lz4
rrsync	Install rrsync script to setup restricted rsync users via ssh logins
ssl
stunnel	Provide helper scripts for using rsync via &gt;=<pkg>net-misc/stunnel</pkg>-4
system-zlib	Use system zlib instead of bundled one. This is incompatible with older rsync releases!
xattr

sys-devel

binutils

Flag	Description
debuginfod	Enable debuginfod support via <pkg>dev-libs/elfutils</pkg> libdebuginfod
default-gold	Set ld to point to ld.gold instead of ld.bfd
gold	Build ld.gold linker
gprofng	Enable the next-generation gprofng profiler
multitarget	Adds support to binutils for cross compiling (does not work with gas)
nls
pgo	Build binutils with Profile Guided Optimization (PGO) and LTO
plugins	Enable plugin support in tools

gettext-tiny

Flag	Description
shim	Install libintl library. Not suitable on glibc systems. On musl systems, passes contents through and translates via musl's libintl. On other systems, provides a no-op library (returns input text with no changes/translations).

sys-fs

ltfs

Flag	Description
snmp

sys-kernel

vanilla-kernel

Flag	Description
savedconfig

sys-libs

glibc

Flag	Description
audit
clone3	Enable the new clone3 syscall within glibc. Can be disabled to allow compatibility with older Electron applications.
compile-locales	build *all* locales in src_install; this is generally meant for stage building only as it ignores /etc/locale.gen file and can be pretty slow
custom-cflags
experimental-loong	Add experimental LoongArch patchset
gd	build memusage and memusagestat tools
hash-sysv-compat	enable sysv linker hashes in glibc for compatibility with binary software (EAC via wine/proton)
headers-only
multiarch	enable optimizations for multiple CPU architectures (detected at runtime)
multilib
multilib-bootstrap	Provide prebuilt libgcc.a and crt files if missing. Only needed for ABI switch.
nscd	Build, and enable support for, the Name Service Cache Daemon
old-kernel	Support the oldest kernel also supported by upstream glibc, otherwise the oldest in the Gentoo tree
profile
selinux
sframe	enable building with sframe backtrace support
ssp	protect stack of glibc internals
stack-realign	Realign the stack in the 32-bit build for compatibility with older binaries at some performance cost
static-pie	Enable static PIE support (runtime files for -static-pie gcc option).
suid	Make internal pt_chown helper setuid -- not needed if using Linux and have /dev/pts mounted with gid=5
systemd

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