diff --git a/share/man/man7/build.7 b/share/man/man7/build.7
--- a/share/man/man7/build.7
+++ b/share/man/man7/build.7
@@ -278,13 +278,33 @@
 and
 .Sy TARGET_ARCH
 must be defined.
+.It Cm packages
+Create a
+.Xr pkg 7
+repository containing packages that can be used to create or upgrade an
+installation of the base system.
+The output repository is placed in the object directory, under
+.Pa ${REPODIR}/${PKG_ABI}
+where
+.Ev REPODIR
+is the base directory where the repository will be created, and
+.Va PKG_ABI
+is the
+.Xr pkg 7
+ABI for the build target, for example,
+.Pa /usr/obj/${SRCDIR}/repo/FreeBSD:15:amd64 .
 .It Cm packageworld
 Archive the results of
 .Cm distributeworld ,
 placing the results in
 .Va DISTDIR .
-This target is used while building a release; see
-.Xr release 7 .
+This target is used while building a
+.Xr release 7
+and is unrelated to building
+.Pa src
+into
+.Xr pkg 7
+targets.
 .It Cm installworld
 Install everything built by a preceding
 .Cm buildworld
@@ -365,6 +385,17 @@
 .Va XDDIR
 defaults to
 .Pa ${TARGET_ARCH}-freebsd .
+.It Cm update-packages
+Create or update the
+.Xr pkg 7
+repository for the base system, optionally created by the
+.Cm packages
+target.
+If an existing repository exists,
+create a new package release in an existing repository updating only
+those packages which have changed since the previous package build.
+Unchanged packages will be copied from the previous build and retain the
+existing version number.
 .It Cm xdev-build
 Builds for the
 .Cm xdev
@@ -411,26 +442,17 @@
 .Pa ${DISTDIR}/kernel/boot/kernel .
 This target is used while building a release; see
 .Xr release 7 .
-.It Cm packages
-Create a
-.Xr pkg 7
-repository containing packages that can be used to create or upgrade an
-installation of the base system.
-The output repository is placed in the object directory, under
-.Pa repo/${PKG_ABI}
-where
-.Va PKG_ABI
-is the
-.Xr pkg 7
-ABI for the build target, for example,
-.Pa /usr/obj/${SRCDIR}/repo/FreeBSD:15:amd64 .
 .It Cm packagekernel
 Archive the results of
 .Cm distributekernel ,
 placing the results in
 .Va DISTDIR .
-This target is used while building a release; see
-.Xr release 7 .
+This target is used while building a
+.Xr release 7
+and is unrelated to building
+.Pa src
+into
+.Cm packages .
 .It Cm kernel
 Equivalent to
 .Cm buildkernel
@@ -658,6 +680,10 @@
 the root of the source tree to build as part of the
 .Cm cross-tools
 target.
+.It Va OBJROOT
+Specify an alternative path to use as the object directory root,
+defaults to
+.Pa /${OBJDIR}/${SRCDIR}/ .
 .It Va PKG_FORMAT
 Specify a package compression format when building
 .Pa src
@@ -682,7 +708,8 @@
 This is currently incompatible with building
 .Pa src
 into
-.Cm packages .
+.Xr pkg 7
+targets.
 Each port must be specified as
 .Ar category Ns Li / Ns Ar port Ns Op Li @ Ns Ar flavor ,
 e.g.
@@ -711,6 +738,16 @@
 The src.conf file controls the components to build.
 See
 .Xr src.conf 5
+.It Va REPODIR
+Specify a base directory to create the repository when building
+.Pa src
+into
+.Xr pkg 7
+targets.
+Defaults to
+.Pa /${OBJROOT}/repo .
+This can also be set in
+.Xr src-env.conf 5 .
 .It Va STRIPBIN
 Command to use at install time when stripping binaries.
 Be sure to add any additional tools required to run