use(): fatal missing IUSE in EAPI 5, bug #449708

diff --git a/bin/phase-helpers.sh b/bin/phase-helpers.sh
index 8a78f372b771ed40860d0a3ba0889593f35c8129..383f9ff5e2bf401286e15d71d8efde2a3dbef6d3 100644 (file)
--- a/bin/phase-helpers.sh
+++ b/bin/phase-helpers.sh
@@ -212,9 +212,15 @@ use() {
 
        # Make sure we have this USE flag in IUSE
        elif [[ -n $PORTAGE_IUSE && -n $EBUILD_PHASE ]] ; then
-               [[ $u =~ $PORTAGE_IUSE ]] || \
+               if [[ ! $u =~ $PORTAGE_IUSE ]] ; then
+                       if [[ ! ${EAPI} =~ ^(0|1|2|3|4|4-python|4-slot-abi)$ ]] ; then
+                               # This is only strict starting with EAPI 5, since implicit IUSE
+                               # is not well defined for earlier EAPIs (see bug #449708).
+                               die "USE Flag '${u}' not in IUSE for ${CATEGORY}/${PF}"
+                       fi
                        eqawarn "QA Notice: USE Flag '${u}' not" \
                                "in IUSE for ${CATEGORY}/${PF}"
+               fi
        fi
 
        local IFS=$' \t\n' prev_shopts=$- ret