diff --git a/tools/tools/git/git-arc.sh b/tools/tools/git/git-arc.sh
--- a/tools/tools/git/git-arc.sh
+++ b/tools/tools/git/git-arc.sh
@@ -152,7 +152,7 @@
     fi
 
     echo '{"names":["'"$diff"'"]}' |
-        arc call-conduit -- phid.lookup |
+        arc call-conduit -- phid.lookup | grep -v '^Warning: ' |
         jq -r "select(.response != []) | .response.${diff}.phid"
 }
 
@@ -167,7 +167,7 @@
 
     tmp=$(mktemp)
     echo '{"names":["'"$diff"'"]}' |
-        arc call-conduit -- phid.lookup > "$tmp"
+        arc call-conduit -- phid.lookup | grep -v '^Warning: ' > "$tmp"
     status=$(jq -r "select(.response != []) | .response.${diff}.status" < "$tmp")
     summary=$(jq -r "select(.response != []) |
          .response.${diff}.fullName" < "$tmp")
@@ -272,7 +272,7 @@
                     "value": ["'"${parentphid}"'"]
                 }
              ]}' |
-            arc call-conduit -- differential.revision.edit >&3
+            arc call-conduit -- differential.revision.edit >&3 | grep -v '^Warning: '
     fi
     rm -f "$msg"
     return 0
@@ -290,13 +290,13 @@
                   "constraints": {"phids": ["'"$reviewid"'"]},
                   "attachments": {"reviewers": true}
               }' |
-        arc call-conduit -- differential.revision.search |
+        arc call-conduit -- differential.revision.search | grep -v '^Warning: ' |
         jq '.response.data[0].attachments.reviewers.reviewers[] | select(.status == "accepted").reviewerPHID')
     if [ -n "$userids" ]; then
         echo '{
                   "constraints": {"phids": ['"$(echo -n "$userids" | tr '[:space:]' ',')"']}
               }' |
-            arc call-conduit -- user.search |
+            arc call-conduit -- user.search | grep -v '^Warning: ' |
             jq -r '.response.data[].fields.username'
     fi
 }