Constant inexplicably not known (comes up as undefined)

Notice: Use of undefined constant CULTURA_YEAR - assumed ‘CULTURA_YEAR’ in CulturaExchangeNode->__construct() (line 105 of /vagrant/web/sites/all/modules/contrib/culturaexchange_migrate/

Other constants also defined in the same file used immediately after this work.

Oh. The module wasn’t enabled.

But still: why didn’t module_load_include work, or throw a warning?

Oh, it doesn’t work for .module files: