Global USE flags

Flag Description Packages
X Build the XCB platform plugin and enable X11 integration 3
abi_mips_n32 2
berkdb 2
bluetooth Build Bluetooth protocol support in socket module 2
brotli 2
dbus Build bindings for the QtDBus module 4
debug 8
doc 8
examples 6
gnutls Enable gnutls ssl backend 2
gssapi Enable support for GSSAPI (<pkg>virtual/krb5</pkg>) 3
gtk Build GTK3 GUI 3
gui Build bindings for the QtGui module 5
icu 2
idn 2
ipv6 2
kerberos 3
ldap 5
libedit 2
mbedtls Use <pkg>net-libs/mbedtls</pkg> as TLS provider 3
memcached Add support for using <pkg>net-misc/memcached</pkg> for lookup tables 2
mysql 3
network Build bindings for the QtNetwork module 2
nls 2
opengl Build bindings for the QtOpenGL module 2
openssl Use <pkg>dev-libs/openssl</pkg> as crypto engine 2
pam 4
postgres 3
psl Enable Public Suffix List (PSL) support. See https://daniel.haxx.se/blog/2024/01/10/psl-in-curl/. 2
python 2
quic Enable support for QUIC (RFC 9000); a UDP-based protocol intended to replace TCP 2
readline 4
samba 2
sasl Enable SASL plugin 3
selinux 9
smartcard Enable smartcard remoting using <pkg>app-emulation/libcacard</pkg> 2
sql Build bindings for the QtSql module 2
sqlite 7
ssl Enable additional crypto algorithms via OpenSSL 12
static-libs 9
svg Build bindings for the QtSvg module 2
symlink Install "pypy3" symlink, making this PyPy slot the default PyPy3 implementation that is used for building Gentoo packages. 2
systemd 3
test 17
wayland 2
websockets Build bindings for the QtWebSockets module 2
widgets Build bindings for the QtWidgets module 2
xml Build bindings for the QtXml module 2
zlib 3
zstd 2

Category USE flags

dev-lang

Flag Description Packages
ensurepip Install the ensurepip module that uses bundled wheels to bootstrap pip and setuptools (if disabled, it will be only possible to use venv `--without-pip`) 2
gdbm 2
jit Enable experimental Just-In-Time compilation support. 2
ncurses 2
tk 2

dev-libs

Flag Description Packages
asm Enables assembly 2

dev-qt

Flag Description Packages
libproxy Use <pkg>net-libs/libproxy</pkg> for automatic HTTP/SOCKS proxy configuration 2

net-wireless

Flag Description Packages
wps Add support for Wi-Fi Protected Setup 2

Local USE flags

app-crypt

qca

Flag Description
botan Enable botan plugin
gcrypt Enable gcrypt plugin
gpg Enable GnuPG plugin
logger Enable logger plugin
nss Enable NSS plugin
pkcs11 Enable PKCS#11 plugin
softstore Enable softstore plugin

tpm2-tss

Flag Description
fapi Enable feature API (requires openssl as crypto backend)
policy Enable policy library (requires openssl as crypto backend)

app-emulation

spice

Flag Description
gstreamer
lz4

dev-lang

pypy

Flag Description
full-stdlib Install complete stdlib as necessary to use PyPy for general purpose programs. By default, only a limited subset that is used when building PyPy3 executables is installed. Note that PyPy2.7's stdlib contains multiple known vulnerabilities.
test-install Install the test suite packages, that are required to run tests in a few reverse dependencies.

python

Flag Description
pgo Optimize the build using Profile Guided Optimization (PGO) by running Python's test suite and collecting statistics based on its performance. This will take longer to build.
tail-call-interp Enable the tail call interpreter. May lead to better performance but is still new and dependent on latest toolchain versions (Clang 19, GCC 15).
valgrind Disable pymalloc when running under <pkg>dev-debug/valgrind</pkg> is detected (may incur minor performance penalty even when valgrind is not used)
wininst Install Windows executables required to create an executable installer for MS Windows

rust

Flag Description
"${ALL_LLVM_TARGETS[@]/llvm_targets_/llvm_targets_}"
"${ALL_RUST_SYSROOTS[@]/rust_sysroots_/rust_sysroots_}"
"(
(
)
)"
big-endian
clippy Install clippy, Rust code linter
cpu_flags_x86_sse2
dist Install dist tarballs (used for bootstrapping)
llvm-libunwind
llvm_targets_BPF
llvm_targets_WebAssembly
lto
miri Install miri, an interpreter for Rust's mid-level intermediate representation (requires USE=nightly, sometimes is broken)
mrustc-bootstrap Use <pkg>dev-lang/mrustc</pkg> to build the bootstrap Rust sysroot from this package's source
nightly Enable nightly (UNSTABLE) features (NOTE: it does not install nightly version, just enables features marked as nightly at time of release)
parallel-compiler Build a multi-threaded rustc (experimental, not tested by upstream)
rust-analyzer Install rust-analyzer, A Rust compiler front-end for IDEs (language server)
rust-src Install rust-src, needed by developer tools and for build-std (cross)
rustfmt Install rustfmt, Rust code formatter
system-llvm Use the system LLVM installation
wasm Build support for the wasm32-unknown-unknown target

dev-libs

libressl

Flag Description
netcat Enable installing TLS-enabled nc(1)

openssl

Flag Description
sslv3 Support for the SSLv3 protocol

softhsm

Flag Description
gost Enable gost algorithm
migration-tool Build db migration tool

dev-perl

Net-SSLeay

Flag Description
minimal

dev-python

m2crypto

Flag Description
abi_mips_n64
abi_mips_o32

pyqt6

Flag Description
designer Build bindings for the QtDesigner module and enable the designer plugin
gles2-only
help Build bindings for the QtHelp module
multimedia Build bindings for the QtMultimedia module
nfc Build bindings for the QtNfc module
pdfium Build bindings for the QtPdf module (uses pdfium from <pkg>dev-qt/qtwebengine</pkg>)
positioning Build bindings for the QtPositioning module
printsupport Build bindings for the QtPrintSupport module
qml Build bindings for the QtQml module and enable the qml plugin
quick Build bindings for the QtQuick module
quick3d Build bindings for the QtQuick3D module
remoteobjects Build bindings for the QtRemoteObjects module
scxml Build bindings for the QtSCXML module
sensors Build bindings for the QtSensors module
serialport Build bindings for the QtSerialPort module
spatialaudio Build bindings for the QtSpatialAudio module
speech Build bindings for the QtTextToSpeech module
testlib Build bindings for the QtTest module
vulkan
webchannel Build bindings for the QtWebChannel module

dev-qt

qtbase

Flag Description
$(
${QT6_IUSE[gui]//+/}
${QT6_IUSE[network]//+/}
${QT6_IUSE[sql]//+/}
${QT6_IUSE[widgets]//+/}
'
concurrent Build Qt6Concurrent module
eglfs Build the EGL Full Screen/Single Surface platform plugin
evdev Enable support for input devices via evdev
journald Log messages using <pkg>sys-apps/systemd</pkg>'s journald rather than output to stderr (override with the QT_FORCE_STDERR_LOGGING=1 env var)
libinput Enable support for input devices via <pkg>dev-libs/libinput</pkg>
printf
renderdoc Enable support for capturing graphic's API calls using <pkg>media-gfx/renderdoc</pkg>
syslog Log messages using syslog rather than output to stderr (override with the QT_FORCE_STDERR_LOGGING=1 env var)
tslib Enable support for touchscreen devices via <pkg>x11-libs/tslib</pkg>
udev

qtnetwork

Flag Description
sctp

mail-mta

postfix

Flag Description
cdb
dovecot-sasl Enable <pkg>net-mail/dovecot</pkg> protocol version 1 (server only) SASL implementation
eai Add support for SMTPUTF8
hardened
ldap-bind Add support for binding to LDAP backend using <pkg>dev-libs/cyrus-sasl</pkg>
lmdb Add support for using <pkg>dev-db/lmdb</pkg> for lookup tables
mbox
nis

net-analyzer

nmap

Flag Description
libssh2 Enable SSH support through <pkg>net-libs/libssh2</pkg>
ncat Install the ncat utility
ndiff Install the ndiff utility
nping Install the nping utility
nse Include support for the Nmap Scripting Engine (NSE)
zenmap Install the GTK+ based nmap GUI, zenmap

net-dialup

freeradius

Flag Description
iodbc
kafka Include support for kafka
mongodb Include support for MongoDB database
odbc
oracle
redis Include support for Redis database
yubikey Include support for ubikey

ppp

Flag Description
activefilter Enables active filter support
atm

net-im

prosody

Flag Description
libevent Use libevent for event handling

net-libs

libssh

Flag Description
pcap Build with PCAP output support
server Build with SSH server support
sftp Build with SFTP support

net-misc

curl

Flag Description
adns
alt-svc Enable alt-svc support
curl_quic_ngtcp2
curl_quic_openssl
curl_ssl_gnutls
curl_ssl_mbedtls
curl_ssl_openssl
curl_ssl_rustls
ech Enable Encrypted Client Hello support
ftp Enable FTP support
gopher Enable Gopher protocol support
hsts Enable HTTP Strict Transport Security
http2
http3 Enable HTTP/3 support
httpsrr Enable HTTPS Resource Record support
imap Enable Internet Message Access Protocol support
pop3 Enable Post Office Protocol 3 support
rtmp Enable RTMP Streaming Media support
rustls Enable Rustls ssl backend
sasl-scram Enable snupport for additional SASL SCRAM-SHA authentication methods via <pkg>net-misc/gsasl</pkg>
smtp Enable Simple Mail Transfer Protocol support
ssh Enable SSH urls in curl using libssh2
telnet Enable Telnet protocol support
tftp Enable TFTP support

openssh

Flag Description
audit
ldns Use LDNS for DNSSEC/SSHFP validation.
legacy-ciphers Enable support for deprecated, soon-to-be-dropped DSA keys. See https://marc.info/?l=openssh-unix-dev&gt;m=170494903207436&gt;w=2.
livecd Enable root password logins for live-cd environment.
pie
security-key Include builtin U2F/FIDO support
static
xmss Enable XMSS post-quantum authentication algorithm

stunnel

Flag Description
stunnel3 Install the stunnel3 wrapper.
tcpd

net-p2p

qbittorrent

Flag Description
webui Install qBittorrent Web UI (qbittorrent-nox)

net-wireless

hostapd

Flag Description
internal-tls Use internal TLSv1 implementation instead of depending on OpenSSL or GnuTLS
netlink Adding support for using netlink to create VLANs
suiteb Adding support for NSA Suite B Cryptography

wpa_supplicant

Flag Description
ap Add support for access point mode
broadcom-sta Flag to help users disable features not supported by broadcom-sta driver
eap-sim Add support for EAP-SIM authentication algorithm
eapol-test Build and install eapol_test binary
fasteap Add support for FAST-EAP authentication algorithm
fils Add support for Fast Initial Link Setup (802.11ai)
hs2-0 Add support for 802.11u and Passpoint for HotSpot 2.0
macsec Add support for wired macsec
mbo Add support Multiband Operation
mesh Add support for mesh mode
p2p Add support for Wi-Fi Direct mode
privsep Enable wpa_priv privledge separation binary
ps3 Add support for ps3 hypervisor driven gelic wifi
qt6
tdls Add support for Tunneled Direct Link Setup (802.11z)
tkip Add support for WPA TKIP (deprecated due to security flaws in 2009)
uncommon-eap-types Add support for GPSK, SAKE, GPSK_SHA256, IKEV2 and EKE
wep Add support for Wired Equivalent Privacy (deprecated due to security flaws in 2004)
wimax Add support for Wimax EAP-PEER authentication algorithm

www-client

netsurf

Flag Description
bmp Bitmap (BMP and ICO) image support via <pkg>media-libs/libnsbmp</pkg>
fbcon
gif
javascript
jpeg
png
rosprite RISC OS Sprite bitmap image support via <pkg>media-libs/librosprite</pkg>
svgtiny Use <pkg>media-libs/libsvgtiny</pkg> instead of <pkg>gnome-base/librsvg</pkg> for SVG support
truetype Use <pkg>media-libs/freetype</pkg> for text in the framebuffer frontend
webp