only use JSON::XS if $ENV{PERL_JSON_XS_USE}

[mohawk2]

No description provided.

[Grinnz]

For my use case, it would be ok if JSON::XS was still used when Cpanel::JSON::XS is not available, but Cpanel::JSON::XS was always preferred (and always installed if XS is possible). Requiring an env variable to activate JSON::XS seems like extra complication unless there is another reason to do that.

If an env variable is needed, it might be nicer to have a more generic one that specifies which backend(s) to prefer.

[plicease]

I think it would be better to have an environmental override for the install and runtime detection, something like JSON_MAYBEXS_IMPLEMENTATION be one of JSON::XS, JSON::PP or Cpanel::JSON::XS. MaybeXS being clever has caused me a fair amount of grief in getting our development, CI and production environments all in sync because of lingering JSON::XS installs or dist install order issues.

[plicease]

To be clear, the cleverness is fine in the absence of an expressed preference, but there should be a way to express a preference.

[karenetheridge]

Cleverness is generally not great. JSON::XS and Cpanel::JSON::XS have drifted too much.. e.g. karenetheridge/JSON-Schema-Modern#79

It's time to kill off the use of JSON::XS for good. Having an explicit environment variable akin to NO_REALLY_HIT_ME_HARDER would still allow for people to fall back to the old behaviour when absolutely needed.