.\" Copyright (c) 2013-2026 Devin Teske <dteske@FreeBSD.org>
.\" Copyright (c) 2021-2026 Faraz Vahedi <kfv@FreeBSD.org>
.\"
.\" SPDX-License-Identifier: BSD-2-Clause
.\"
.Dd August 2, 2026
.Dt SYSCONF-SRC 8
.Os
.Sh NAME
.Nm "sysconf src"
.Nd configure the src-env.conf / make.conf / src.conf triad
.Sh SYNOPSIS
.Nm sysconf
.Cm src
.Op Fl ceFinNqsvVx
.Op Fl j Ar jail | Fl R Ar dir
.Op Fl f Ar file
.Ar name Ns Op Ns Oo +|- Oc Ns = Ns Ar value
.Ar ...
.Nm sysconf
.Cm src
.Op Fl eFnNqvV
.Op Fl f Ar file
.Fl a
.Nm sysconf
.Cm src
.Op Fl E
.Fl l | L
.Sh DESCRIPTION
The
.Cm src
target of
.Xr sysconf 8
is the
.Pa /usr/src
build audience:
it consults the same triad
.Xr make 1
uses when building the source tree
.Po
.Pa src-env.conf ,
then
.Pa make.conf ,
then
.Pa src.conf
.Pc ,
honoring
.Ev SRC_ENV_CONF ,
.Ev __MAKE_CONF ,
and
.Ev SRCCONF
when set.
See
.Xr bsdconf_format 3
and
.Xr src.conf 5 .
Shared options are in
.Xr sysconf 8 ;
authoritative-file and removal policy in
.Xr sysconf-targets 8 ;
.Ql +=
and
.Ql -=
semantics match
.Xr sysconf-make 8 .
.Pp
New directives are written to
.Pa src.conf
.Pq or the path in Ev SRCCONF ;
an existing definition is rewritten in the file that last set it.
There is no separate
.Ql src-env
keyword;
use
.Cm src
or
.Fl f
for surgical edits of
.Pa src-env.conf .
.Pp
.Ql WITH_*
and
.Ql WITHOUT_*
are presence knobs
.Po
.Xr src.conf 5
ignores the value; empty
.Ql name=
is the preferred spelling
.Pc .
Prefer
.Fl s
.Ar name
over
.Ar name Ns =
when only presence matters;
.Fl s
leaves an already-defined knob
.Pq any value
unchanged and echoes
.Ql (present) (unchanged) .
An explicit
.Ar name Ns =
.Pq including empty
always writes the requested value, and a change of placeholder echoes
.Ql name: old -> new .
.Fl s
appends to the preferred write file and does not remove an inverse
.Ql WITH_
or
.Ql WITHOUT_
for the same option.
Reads show
.Ql name (present)
for any assigned value;
with
.Fl e ,
the real assignment
.Po
e.g.
.Ql name=
or
.Ql name=t
.Pc ;
with
.Fl n ,
that same value alone
.Pq empty when the assignment is Ql name= .
Writing
.Ql WITH_ Ns Ar foo Ns =no
warns as on the
.Cm make
target
.Pq see Xr sysconf-make 8 ;
.Pa /usr/src
make evaluates such assignments via
.Pa bsd.opts.mk
and
.Pa src.opts.mk .
.Pp
.Va WITHOUT_MODULES
is not a presence knob:
its value is a module reject list, so
.Fl s
is rejected and reads print the module list rather than
.Ql (present) .
Set it with a normal assignment
.Pq e.g. Va WITHOUT_MODULES Ns = Ns Ar plip .
.Pp
This target has no defaults file;
.Fl d ,
.Fl D ,
and
.Fl A
are errors.
.Sh ENVIRONMENT
.Bl -tag -width "SRC_ENV_CONF"
.It Ev SRC_ENV_CONF
Path of
.Pa src-env.conf
.Pq default Pa /etc/src-env.conf ;
verbatim,
not subject to
.Fl R .
.It Ev __MAKE_CONF
Path of
.Pa make.conf
.Pq default Pa /etc/make.conf ;
verbatim,
not subject to
.Fl R .
.It Ev SRCCONF
Path of
.Pa src.conf
.Pq default Pa /etc/src.conf ;
verbatim,
not subject to
.Fl R .
Also the preferred write file for new directives.
.El
.Sh FILES
.Bl -tag -width "/etc/src-env.conf" -compact
.It Pa /etc/src-env.conf
First file of the triad.
.It Pa /etc/make.conf
Middle file of the triad.
.It Pa /etc/src.conf
Last file and preferred write target.
.El
.Sh EXAMPLES
.Dl sysconf src -s WITHOUT_LLDB
.Dl sysconf src WITHOUT_LLDB=
.Dl sysconf src WITHOUT_LLDB
.Dl sysconf src -x WITHOUT_LLDB
.Dl sysconf src -V CFLAGS
.Sh SEE ALSO
.Xr make 1 ,
.Xr bsdconf_format 3 ,
.Xr src.conf 5 ,
.Xr sysconf 8 ,
.Xr sysconf-make 8 ,
.Xr sysconf-targets 8
.Sh HISTORY
The
.Nm sysconf
utility first appeared in
.Fx 16.0 .
.Sh AUTHORS
.An Devin Teske Aq Mt dteske@FreeBSD.org
.An Faraz Vahedi Aq Mt kfv@FreeBSD.org