The deal President Trump called “incredible” and Gov. Scott Walker hailed as a “once-in-a-century” opportunity to bring the electronic manufacturing giant Foxconn to Wisconsin wouldn’t generate profits for the state until 2042, a new legislative analysis projects.

The state’s Legislative Fiscal Bureau, a nonpartisan agency that analyzes proposed economic investments, looked at Walker’s bid last month to bring a new flat-screen-display factory to the state in exchange for a roughly $3 billion-incentives package.

Foxconn said it would break ground in southeastern Wisconsin and hire 3,000 workers there over the next four years, with the “potential” to create 13,000 jobs.

If the company hits that growth target, Wisconsin would break even after 25 years, said Rob Reinhardt, a program manager who worked on the report. If 13,000 jobs never materialize, it could take decades longer.

“We kind of dig a hole for ourselves,” Reinhardt said.

State officials, however, maintain the deal would bring more prosperity.

“The state of Wisconsin is investing in a once-in-a-lifetime economic development opportunity that will be transformational as the state will become home to the only LCD manufacturing facility outside of Asia,” said Mark Maley, spokesman for the Wisconsin Economic Development Corporation. “Bringing Foxconn to Wisconsin will have an estimated annual economic impact of $7 billion that will touch every region of the state.”

That value, he added, will come from generating an estimated 13,000 direct and 22,000 indirect jobs.

Under Walker’s terms, Wisconsin, which competed with six other states to attract the business, would provide Foxconn with up to $2.85 billion in state income tax credits, which could be made in cash payments, and up to $150 million in sales tax breaks over a 15-year period.

The state legislature was expected to vote on the package early this month, but as of Wednesday, Wisconsin’s Senate Majority Leader Scott Fitzgerald (R-Juneau) told local reporters that he did not yet have the votes to approve it.

“We should be cautious,” he said, according to the Milwaukee Journal Sentinel.

The Fiscal Bureau’s analysis, released Tuesday, said other factors could delay the investment's payoff.

Wisconsin has an unusually low unemployment rate (3.2 percent), well below the country’s 4.3 percent. Employers there already complain about having trouble finding workers. (As The Post’s Chico Harlan reported last week, some are easing the labor demand with robots.)

If Foxconn fills jobs with workers from neighboring Illinois, where the unemployment rate is 4.7 percent, analysts predict the deal won’t start making money for Wisconsin until 2045.

Walker's office has said that community colleges and technical schools will adapt to meet Foxconn’s needs. The factory isn’t slated to open until at least 2021.

The Taiwanese giant,  which makes gadgets for Apple, Google, Amazon and other companies, said it would spend $10 billion to build the 20 million-square-foot plant and pay workers an average annual wage of $53,000. It would hire Wisconsin construction workers and purchase building materials in the state — a further boost to the local economy, Walker’s office has noted.

“The company’s investment is $10 billion, which is $6.70 of private investment for every $1 of public funds,” said Tom Evenson, a spokesman for Walker. “This is an excellent investment for our entire state.”

The governor has maintained the deal will spark more prosperity in Wisconsin.

“We are calling this development ‘Wisconn Valley,’ ” he said last month at the White House, unveiling the development news alongside Trump, “because we believe this will have a transformational effect on Wisconsin, just as Silicon Valley transformed the San Francisco Bay area.”