Box office prognosticators have been warning Fox and theater owners not to expect diddly from the opening of the $170 million “Alita: Battle Angel,” which James Cameron handed to Robert Rodriguez in a “Hold my beer” move meant to expedite his “Avatar” sequels.

Cameron was going to direct the manga adaptation, and his imprint is all over the tin-eared script and generally whimsy free enterprise.

We were told, “Well, it won’t open huge — only $37 million over the Presidents Day Weekend.” A $50-65 opening would have been healthy, considering the budget, with foreign territories carrying it easily into the black.

Not to be. A non-franchise sci-fi fantasy with a hint of ill-fated “This’ll never work” robot/human romance, this reminder of why Japan’s population is shrinking won’t do much better than $27 million, per Deadline.com, based on opening night-before and opening day numbers.

Ouch.

Indifferent reviews didn’t help. It’s joyless and simple-minded, and the fact that its in 3D doesn’t matter. Bombs away.

It’ll barely best an underwhelming “Lego Movie” sequel, “The Lego Movie 2: The Second Part” which on its second weekend is also on track to collect $27 million or so.

Rebel Wilson’s blase rom-com send up “Isn’t it Romantic?” isn’t swimming in Valentine’s Week cash. It did decent business Wed and Thursday is falling off the to point where it’ll fall short of $13 million over the weekend by midnight Monday — $18-19 million since Wed. Nobody’s leaping from the ledge over this one, at least.

“What Men Want” is having a decent second weekend — nothing to brag or cry about.

The other new opening is a desultory horror sequel, wringing the last few frights and laughs out of Jessica Rothe’s sorority girl “Buffy” surviving a “Groundhog Day” of grisly deaths. Hers. “Happy Death Day 2U” is headed towards a $10-11 million opening.

“Cold Pursuit” is headed to an icy grave, and “Green Book” and “Aquaman” are finally long gone from the Top Ten.