Index: head/CHANGES
===================================================================
--- head/CHANGES
+++ head/CHANGES
@@ -10,6 +10,33 @@
 
 All ports committers are allowed to commit to this file.
 
+20171130:
+AUTHOR: mat@FreeBSD.org
+
+  Flavors are a way to have multiple variations of a port.  The port is built
+  multiple times, with the variations.  To declare flavors, set the FLAVORS
+  variable to the flavors you want defined.  The first flavor will be the
+  default:
+
+    FLAVORS=   flavor1 flavor2
+
+  The flavors MUST be lowercase, and can contain [[:lower:][:digit:]_].
+
+  Then, when building the port, pass the FLAVOR as an argument after make to
+  select the flavor.
+
+    $ make install FLAVOR=flavor2
+
+  In the port, you can then change the behavior depending on the value of the
+  FLAVOR variable.  Note that the different flavors MUST have different
+  PKGNAMEs.  Be sure to guard against an empty FLAVOR variable by using
+  ${FLAVOR:U}:
+
+    .if ${FLAVOR:U} == flavor2
+    PKGNAMESUFFIX=	-foo
+    OPTIONS_DEFAULT+=   FOO
+    .endif
+
 20171020:
 AUTHOR: ak@FreeBSD.org
 
Index: head/Mk/Scripts/qa.sh
===================================================================
--- head/Mk/Scripts/qa.sh
+++ head/Mk/Scripts/qa.sh
@@ -841,9 +841,26 @@
 	return $rc
 }
 
+flavors()
+{
+	local rc pkgnames uniques
+	rc=0
+	if [ -n "${FLAVOR}" ]; then
+		pkgnames=$(make -C "${CURDIR}" flavors-package-names|sort)
+		uniques=$(echo "${pkgnames}"|uniq)
+		if [ "$pkgnames" != "${uniques}" ]; then
+			err "Package names are not uniques with flavors:"
+			make -C "${CURDIR}" pretty-flavors-package-names >&2
+			err "maybe use <flavor>_PKGNAMEPREFIX/SUFFIX".
+			rc=1
+		fi
+	fi
+	return ${rc}
+}
+
 checks="shebang symlinks paths stripped desktopfileutils sharedmimeinfo"
 checks="$checks suidfiles libtool libperl prefixvar baselibs terminfo"
-checks="$checks proxydeps sonames perlcore no_arch gemdeps"
+checks="$checks proxydeps sonames perlcore no_arch gemdeps flavors"
 
 ret=0
 cd ${STAGEDIR}
Index: head/Mk/bsd.port.mk
===================================================================
--- head/Mk/bsd.port.mk
+++ head/Mk/bsd.port.mk
@@ -1065,8 +1065,7 @@
 .if !defined(_FLAVOR)
 _FLAVOR:=	${FLAVOR}
 .endif
-# XXX: We have no real FLAVORS support in ports or tools yet.
-#PORTS_FEATURES+=	FLAVORS
+PORTS_FEATURES+=	FLAVORS
 MINIMAL_PKG_VERSION=	1.6.0
 
 _PORTS_DIRECTORIES+=	${PKG_DBDIR} ${PREFIX} ${WRKDIR} ${EXTRACT_WRKDIR} \
@@ -1082,18 +1081,6 @@
 
 .include "${PORTSDIR}/Mk/bsd.commands.mk"
 
-.if !empty(FLAVOR)
-.  if empty(FLAVORS)
-IGNORE=	FLAVOR is defined while this port does not have FLAVORS.
-.  elif ! ${FLAVORS:M${FLAVOR}}
-IGNORE=	Unknown flavor '${FLAVOR}', possible flavors: ${FLAVORS}.
-.  endif
-.endif
-
-.if !empty(FLAVORS) && empty(FLAVOR)
-FLAVOR=	${FLAVORS:[1]}
-.endif
-
 # Do not leak flavors to childs make
 .MAKEOVERRIDES:=	${MAKEOVERRIDES:NFLAVOR=*}
 
@@ -1470,6 +1457,32 @@
 .include "${USESDIR}/${f:C/\:.*//}.mk"
 .endfor
 
+.if !empty(FLAVORS)
+.  if ${FLAVORS:Mall}
+DEV_ERROR+=		"FLAVORS cannot contain 'all', it is a reserved value"
+.  endif
+.  for f in ${FLAVORS}
+.    if ${f:C/[[:lower:][:digit:]_]//g}
+_BAD_FLAVOR_NAMES+=		${f}
+.    endif
+.  endfor
+.  if !empty(_BAD_FLAVOR_NAMES)
+DEV_ERROR+=		"FLAVORS contains flavors that are not all [a-z0-9_]: ${_BAD_FLAVOR_NAMES}"
+.  endif
+.endif
+
+.if !empty(FLAVOR)
+.  if empty(FLAVORS)
+IGNORE=	FLAVOR is defined (to ${FLAVOR}) while this port does not have FLAVORS.
+.  elif ! ${FLAVORS:M${FLAVOR}}
+IGNORE=	Unknown flavor '${FLAVOR}', possible flavors: ${FLAVORS}.
+.  endif
+.endif
+
+.if !empty(FLAVORS) && empty(FLAVOR)
+FLAVOR=	${FLAVORS:[1]}
+.endif
+
 EXTRACT_SUFX?=			.tar.gz
 
 .if defined(USE_LINUX_PREFIX)
@@ -1562,6 +1575,9 @@
 				LOCALBASE=${LOCALBASE} \
 				"STRIP=${STRIP}" \
 				TMPPLIST=${TMPPLIST} \
+				CURDIR='${.CURDIR}' \
+				FLAVOR=${FLAVOR} \
+				FLAVORS='${FLAVORS}' \
 				BUNDLE_LIBS=${BUNDLE_LIBS} \
 				LDCONFIG_DIR="${LDCONFIG_DIR}" \
 				PKGORIGIN=${PKGORIGIN} \
@@ -4025,11 +4041,17 @@
 fetch-specials:
 	@${ECHO_MSG} "===> Fetching all distfiles required by ${PKGNAME} for building"
 	@for dir in ${_DEPEND_SPECIALS}; do \
+		case $${dir} in \
+			*@*) \
+				flavor=$${dir#*@}; \
+				dir=$${dir%@*}; \
+				;; \
+		esac; \
 		case $$dir in \
 		/*) ;; \
 		*) dir=${PORTSDIR}/$$dir ;; \
 		esac; \
-		(cd $$dir; ${MAKE} fetch); \
+		(cd $$dir; ${MAKE} FLAVOR=$${flavor} fetch); \
 	done
 .endif
 
@@ -4323,6 +4345,7 @@
 INDEX_OUT=/dev/stdout
 .  endif
 
+.  if empty(FLAVORS) || defined(_DESCRIBE_WITH_FLAVOR)
 describe:
 	@(${ECHO_CMD} -n "${PKGNAME}|${.CURDIR}|${PREFIX}|"; \
 	${ECHO_CMD} -n ${COMMENT:Q}; \
@@ -4337,6 +4360,13 @@
 			;; \
 		esac; \
 	done < ${DESCR}; ${ECHO_CMD}) >>${INDEX_OUT}
+.  else # empty(FLAVORS)
+describe: ${FLAVORS:S/^/describe-/}
+.   for f in ${FLAVORS}
+describe-${f}:
+	@cd ${.CURDIR} && ${MAKE} -B FLAVOR=${f} -D_DESCRIBE_WITH_FLAVOR describe
+.   endfor
+.  endif # empty(FLAVORS)
 . endif
 
 www-site:
@@ -4616,6 +4646,25 @@
 .if !defined(DEVELOPER)
 	@${ECHO_MSG} "/!\\ To run stage-qa automatically add DEVELOPER=yes to your environment /!\\"
 .endif
+.endif
+
+pretty-flavors-package-names: .PHONY
+.if empty(FLAVORS)
+	@${ECHO_CMD} "no flavor: ${PKGNAME}"
+.else
+.for f in ${FLAVORS}
+	@${ECHO_CMD} -n "${f}: "
+	@cd ${.CURDIR} && ${MAKE} -B FLAVOR=${f} -V PKGNAME
+.endfor
+.endif
+
+flavors-package-names: .PHONY
+.if empty(FLAVORS)
+	@${ECHO_CMD} "${PKGNAME}"
+.else
+.for f in ${FLAVORS}
+	@cd ${.CURDIR} && ${MAKE} -B FLAVOR=${f} -V PKGNAME
+.endfor
 .endif
 
 # Fake installation of package so that user can pkg delete it later.
Index: head/Tools/scripts/MOVEDlint.awk
===================================================================
--- head/Tools/scripts/MOVEDlint.awk
+++ head/Tools/scripts/MOVEDlint.awk
@@ -80,15 +80,44 @@
     }
     lastdate = $3
 
+    from_flavor=""
+    if ($1 ~ "@") {
+        from_flavor=$1
+        sub("@.*", "", $1)
+        sub(".*@", "", from_flavor)
+    }
+
     if (system("test -f " portsdir "/" $1 "/Makefile")) {
         delete missing[$1]
     } else {
-        printf "%5d: %s must be marked as resurrected\n", NR, $1 | sort
+        if (from_flavor != "") {
+            if (!system("test \"" from_flavor "\" = \"`make -C " portsdir "/" $1 " -VFLAVORS:M" from_flavor "`\"")) {
+                printf "%5d: %s still has the %s flavor\n", NR, $1, from_flavor | sort
+            }
+            # No else because the port is there but does not have the flavor,
+            # so it should be ok.
+        } else {
+            printf "%5d: %s must be marked as resurrected\n", NR, $1 | sort
+        }
     }
 
     if ($2) {
+        to_flavor=""
+        if ($2 ~ "@") {
+            to_flavor=$2
+            sub("@.*", "", $2)
+            sub(".*@", "", to_flavor)
+        }
+
         if (system("test -f " portsdir "/" $2 "/Makefile"))
             missing[$2] = NR
+        else
+            if (to_flavor != "") {
+                if (system("test \"" to_flavor "\" = \"`make -C " portsdir "/" $2 " -VFLAVORS:M" to_flavor "`\"")) {
+                    printf "%5d: %s does not have the %s flavor\n", NR, $2, to_flavor | sort
+                    error[NR] = 1
+                }
+            }
     }
 
 #    Produces too many false positives