I am using Data::Dump which has a drop in replacement named Data::Dump::Color. I wanted to conditionally/programmatically load a specific module.

if ($color) {
    use Data::Dump::Color;
} else {
    use Data::Dump;
}

This doesn't work because use statements are run before ANY other code is run. The above code will load BOTH modules, because use always runs. Instead you have to use require.

if ($color) {
    require Data::Dump::Color;
    Data::Dump::Color->import();
} else {
    require Data::Dump;
    Data::Dump->import();
}

Calling require does not automatically import all the exported functions, so you have to specifically call the include() function.