Line 12 of JSON::WebToken is:

use JSON qw(encode_json decode_json);

Perl's use statement is shorthand for:

BEGIN {
  require JSON;
  JSON->import(qw(encode_json decode_json));
}

[download]

.. and the key feature of require is that it loads the module only if it has not already been loaded. It checks that by looking in %INC.

My guess then is that JSON::XS is poking a value into %INC to make it look as if JSON itself has also already been loaded - but failing to define the JSON::import() method.

In the JSON::XS SYNOPSIS section I see:

  # Note that JSON version 2.0 and above will automatically use JSON::
+XS
  # if available, at virtually no speed overhead either, so you should
  # be able to just:

  use JSON;

  # and do the same things, except that you have a pure-perl fallback 
+now.

[download]

.. so I suspect if you change your mylib::json to use JSON instead of use JSON::XS, it will probably make the problem disappear. If my diagnosis is correct, though, I'd call this a bug in JSON::XS.

In reply to Re: Undefined import name priority issue? by hv
in thread Undefined import name priority issue? by sectokia

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