nix-super/doc/manual/troubleshooting.xml

<appendix>
  <title>Troubleshooting</title>

  <para>This section provides solutions for some common problems.</para>

  <sect1><title>Berkeley DB: <quote>Cannot allocate memory</quote></title>

  <para>Symptom: Nix operations (in particular the
  <command>nix-store</command> operations <option>--gc</option>,
  <option>--verify</option>, and <option>--clear-substitutes</option>
  — the latter being called by <command>nix-channel
  --update</command>) failing:

<screen>
$ nix-store --verify
error: Db::del: Cannot allocate memory</screen>

   Possible solution: make sure that no Nix processes are running,
   then do:

<screen>
$ cd /nix/var/nix/db
$ rm __db.00*</screen>

  </para>

  
  </sect1>
  
	
</appendix>