UnsupportedFeatureError: set returning functions are not supported in simple expressions

[andrephilipsson]

• EdgeDB Version: 2.1
• OS Version: macOS 12.5.1

Steps to Reproduce:

1. Running edgedb migration create && edgedb migrate from this schema:

module default {
  global current_user -> uuid;

  type User {
    access policy limit_to_current_user
      allow all
      using (global current_user ?= .id);
  }

  type LoginCode {
    required property code -> str;

    required link user -> User;

    constraint exclusive on ((.user, .code));

    access policy limit_to_current_user
      allow all
      using (global current_user ?= .user.id);
  }
}

results in:

Created dbschema/migrations/00001.edgeql, id: m1uhrnii6aymztxa73vr5bnnrf7cjatxdcd5oouqpk72elj6p6i3wq
edgedb error: UnsupportedFeatureError: set returning functions are not supported in simple expressions

2. Remove the access policy from the User type:

 module default {
   global current_user -> uuid;
 
-  type User {
-    access policy limit_to_current_user
-      allow all
-      using (global current_user ?= .id);
-  }
+  type User {}
 
   type LoginCode {
     required property code -> str;

If we remove the unsuccessful migration with rm dbschema/migrations/00001.edgeql and then run edgedb migration create && edgedb migrate again, the result is:

Created dbschema/migrations/00001.edgeql, id: m1pebzmkoklhrqjubkqydozbxsivsdtkvz2o4arxpdeivm45pderba
Applied m1pebzmkoklhrqjubkqydozbxsivsdtkvz2o4arxpdeivm45pderba (00001.edgeql)

3. If we then add back the access policy to the User type:

 module default {
   global current_user -> uuid;
 
-  type User {}
+  type User {
+    access policy limit_to_current_user
+      allow all
+      using (global current_user ?= .id);
+  }
 
   type LoginCode {
     required property code -> str;

and run edgedb migration create && edgedb migrate again:

Created dbschema/migrations/00002.edgeql, id: m1z66inv2m6nxbebbt5lvv7zv7ksghemwkxpeemq6uqg7pvht72nnq
Applied m1z66inv2m6nxbebbt5lvv7zv7ksghemwkxpeemq6uqg7pvht72nnq (00002.edgeql)

[elprans]

Should be fixed in #4248 due in 2.2 in a couple of days.