Based on the list of installed Debian packages you've posted:

Debian GNU/Linux 10

ii  libjson-perl                          4.02000-1     all          m
+odule for manipulating JSON-formatted data
ii  libjson-xs-perl                       3.040-1+b1    amd64        m
+odule for manipulating JSON-formatted data (C/XS-accelerated)

[download]

It's likely that the problem is that the JSON::XS module is installed, so JSON wants to use it, but it is too old (3.040), so it doesn't have the boolean_values method.

The best solution would be upgrading JSON::XS to 4.0 or newer, but this may be problematic if there is no Debian package available for your OS version.

Alternatively, you could force JSON to use the JSON::PP backend, which should support the boolean_values method, at the expense of being slower.

By the way, you could probably ditch the JSON module altogether and use either JSON::PP or JSON::XS explicitly, because it's only a convoluted and slow wrapper with little to no useful new functionality.

In reply to Re: Issues using boolean_values in JSON v4.02 by kikuchiyo
in thread Issues using boolean_values in JSON v4.02 by bc3-au

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