It's worth noting that the default behavior of no autovivification doesn't disable it in case of assignments aka store

Which is great because that's DWIM for most. But surprising given the name of the pragma...

  
  DB<5> no autovivification; $h->{a}{b}{c} = 42

  DB<6> x $h
0  HASH(0xb400007e0b2fd8b8)
   'a' => HASH(0xb400007e0b2ea7f8)
      'b' => HASH(0xb400007e0b2eac30)
         'c' => 42
  DB<7>
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From the autovivification docs

Possible unimports:

• no autovivification qw<fetch store exists delete>;

But store is not default

• no autovivification; # defaults to qw<fetch exists delete>