The commission called on the government to invest heavily in the revitalization of indigenous languages, noting it spends just 9.1 million Canadian dollars on programs supporting dozens of them each year, compared with 348.2 million Canadian dollars on the country’s two official languages, French and English.

In December, Prime Minister Justin Trudeau’s government increased annual funding for indigenous languages to 23 million Canadian dollars and promised to introduce an Indigenous Languages Act to protect them. To date, that has not happened.

“This is fundamental to our survival as indigenous people,” said Perry Bellegarde, national chief of the Assembly of First Nations, which represents 634 reserves in Canada. He was optimistic that the law would be introduced in summer next year, and come with “as much resources to promote the languages as they did to kill them.”

After a long day of stumbling over pronunciation, Mr. Russ, one of the actors, sat by the wood stove with his script open on his lap, enjoying Mr. Williams’s music for a moment. He had circled every line he found difficult, which were all 37.

His relaxation did not last long. “I’m starting to feel overwhelmed,” he said, heading outside to practice.

Two weeks was not enough to learn pronunciation, let alone memorize his lines. Then, he had to learn how to act.