Turns out not having any penalty for the executive failing to apply the law is a mistake.

Who could have predicted this.

There is a penalty just congress has to enforce it.

The only penalty congress can enforce on the executive is cutting the budget of things the executive wants funded.

Also this only matters if the Fed is independent. If it’s not, the President can direct it to purchase unlimited treasury bonds, effectively printing unlimited money to fund any program it wants.

Paired with this administration’s assertion of impoundment powers and the pocket rescission, the Congress’s power of the purse is completely neutered in both directions. The executive can decline to spend whatever it doesn’t want to, and it can fund anything it does want.

Recklessly funding the government off of the Fed’s balance sheet will of course cause all sorts of nasty economic effects, but that’s exactly why you need to print money! So your massive immigration enforcement apparatus (newly full of ideological minions thanks to the current hiring surge) can go and assert powers of process-free expedited removal throughout the entire country (per DOJ memo from week 1).

So the economic consequences hardly matter: you simply deport whoever complains.

It turns out that if you won't impeach an executive on any principle whatsoever, you may as well grab the boot and put it on your own neck.

Maybe the best solution is to adopt a parliamentary system of government? With the executive formally subordinated to the legislature, it can’t spend money against the legislative majority’s wishes, because if it upsets the legislature, the legislature votes it out of power (commonly with no supermajority required, just a simple majority vote in the more numerous legislative house)

Absolutely. There's a reason the US didn't replicate its own structure when it set up governments in Europe and Japan.

or impeachment?

I mean I’m as anti-Trump as the next, but didn’t the bill say it could be delayed to finalize a sale to American owners?

You could make the case that this sale means the Trump admin actually didn’t break the rules here.

It said it could be delayed with some pretty specific parameters. Quoting the Congressional Research Service report on the bill:

"The President can grant a one-time extension of up to 90 additional days when a path to a qualified divestiture has been identified, there is evidence of 'significant' progress toward executing the divestiture, and there are legally binding agreements in place to enable the divestiture."

One could argue all day about whether or not there was an identified path or evidence of significant progress, but certainly there weren't legally binding agreements in place at any point, and the deadline has been extended far more than once.

Trump is ignoring the law. The DoJ has asserted that Trump can ignore the law because it would interfere with his duty to "take care of the national security and foreign affairs of the United States." It is unclear what, if any law, could not be ignored under this doctrine.

Only one extension was allowed.