Magento 2 – How to Force-Run Module Install Script

I have added some install data to my module (EAV attributes), and it doesn't look like it's working. However, I don't seem to get any relevant errors in the logs, and am a bit lost on whether the install script ever ran in the first place. I tried two ways to run it:

• Disable/enable module
• Running setup:upgrade

Is there a way to force-run just my install script? If not, does setup:upgrade always run it, and if so, which log should I be looking at?

Edit: Here is the relevant part of the install data script:

$customerSetup->addAttribute(Customer::ENTITY, 'some_action_timestamp', [
        'type' => 'int',
        'label' => 'Some action timestamp',
        'input' => 'text',
        'required' => false,
        'visible' => false,
        'user_defined' => true,
        'sort_order' => 1000,
        'position' => 1000,
        'system' => 0,
    ]);

    $attribute = $customerSetup->getEavConfig()->getAttribute(Customer::ENTITY, 'some_action_timestamp')
        ->addData([
            'attribute_set_id' => $attributeSetId,
            'attribute_group_id' => $attributeGroupId,
            'used_in_forms' => ['adminhtml_customer'],
        ]);

    $attribute->save();