And it came out hours before Snyder took another bankruptcy victory lap at a Detroit Economic Club meeting, where he remarked about the "absolutely incredible" progress Detroit has made since emerging from bankruptcy.

The report is a blinking yellow light for business, civic and political leaders — particularly Gov.-elect Gretchen Whitmer — that Detroit's financial stability is not a sure bet, even as billionaire Dan Gilbert constructs a new skyscraper, Ford Motor Co. starts to build out a 5,000-employee autonomous vehicle campus in Corktown and other capital pours into the downtown area.

Property tax revenue "remains weak" outside of the 7.2 square miles of greater downtown, Moody's analysts wrote, a reflection that the "comeback" hasn't reached the city's vast neighborhoods yet.

"Detroit is left with a combustible brew: a reliance on volatile revenue sources and growing fixed costs," Moody's analysts wrote.

The city's property tax base is "trending upward" after a citywide reassessment lowered values to be more in line with market prices, said John Hill, Detroit's outgoing chief financial officer.

Housing sales, utility startups and building permits for new residential construction suggests "the city has turned the corner on the population declines of the past," Hill said.

The report does note Mayor Mike Duggan's administration is working to address the looming resumption of normal pension payments in 2024, when the annual bill is estimated to top $143 million.

The $816 million in "grand bargain" contributions from the state and philanthropic foundations are helping give Detroit a 10-year break from making full contributions to its retirement systems.

With approval from City Council, the city's CFO established a trust fund to sock away $335 million over eight years and use the funds to soften the budgetary blow the city will sustain when the pension bills come due again.

Perhaps the biggest alarm bell in the Moody's report is the rating agency's commentary on the Detroit Public Schools Community District, which Snyder and the Legislature rescued from the brink of financial collapse in June 2016.

"The (public) school district could also become a major drag on revitalization beyond downtown," Moody's analysts warn, reflecting on growing concerns that residential population growth in greater downtown can't be sustained without quality public schools for workers filling once-vacant office space.

The report didn't delve into the next looming crisis at Detroit's public schools: The reorganized school district has no ability to borrow money to fix more than $500 million in capital improvement needs for more than 100 occupied school buildings spanning 10 million square feet.

The Legislature's $617 million bailout of the district's operating ledger blocks DPSCD from accumulating any new capital debt until 2040.

The Detroit school district's existing 13 mills for capital improvements is dedicated to paying $1.63 billion in old debt from eight capital bond issues between 1998 and 2010.

The analysts at Moody's issued the report ahead of Detroit selling $115 million of general obligation bonds that the Wall Street rating agency has assigned a Ba3 credit rating, which is still deemed non-investment grade or junk bonds in the eyes of investors.

The city plans to sell the bonds to finance a series of capital improvement projects at the DDOT Coolidge bus terminal, neighborhood parks, the Charles H. Wright Museum of African American History and Aretha Franklin Park (formerly Chene Park), according to a memo sent Oct. 22 to City Council members.

The bond proceeds also will fund economic development projects and an expansion of the greenlight crime-monitoring camera systems at businesses across the city, according to the memo.

More importantly, Hill said, the bond sale will mark the first time the city has entered the capital markets without the direct assistance of the State of Michigan since prior to state emergency financial intervention began in 2012.

City officials are meeting with prospective investors the week after Thanksgiving, Hill said.

"We believe that the market right now is looking for, especially at the end of year, places to place money," Hill told Crain's. "People will be banking on the city's future and the fact that we're back in the market."

Editor's note: This story has been edited to correct the area of greater downtown Detroit.