[tom_mellior]

For whatever it's worth, on a somewhat-current Linux Mint, with the test from https://github.com/stedolan/jq/issues/1387:

System jq:

    $ jq --version
    jq-1.6
    $ echo '{"number":288230376151711744}' | jq '.number'
    288230376151711740

Fresh compile from source according to the build instructions at https://github.com/stedolan/jq:

    $ ./configure --with-oniguruma=builtin && make -j8
    $ ./jq --version
    jq-1.6-137-gd18b2d0-dirty
    $ echo '{"number":288230376151711744}' | ./jq '.number'
    288230376151711744

Alternatively:

    $ ./configure --with-oniguruma=builtin --enable-decnum=no && make -j8
    $ echo '{"number":288230376151711744}' | ./jq '.number'
    288230376151711740

So the basic bug is fixed, jq has included a bignum library for > 2 years. I don't know if Mint (and thus presumably Ubuntu, and thus possibly Debian) includes an older version of jq or sets nonstandard user-unfriendly flags on purpose, but I'm somewhat underwhelmed in either case.