recycling after changing the tick specification of a block if it involves an expression results in a erroneous error

[petrelharp]

Open this script in SLiMgui:

initialize() {
	initializeMutationRate(1e-7);
	initializeMutationType("m1", 0.5, "f", 0.0);
	initializeGenomicElementType("g1", m1, 1.0);
	initializeGenomicElement(g1, 0, 99999);
	initializeRecombinationRate(1e-8);
	defineConstant("X", 10);
}

1 early() { sim.addSubpop("p1", 500); }

10 late() { sim.simulationFinished(); }

This runs fine. But change the last line to

10+1 late() { sim.simulationFinished(); }

and hit the Recycle button; and it produces the following error:

ERROR (SLiMEidosBlock::SLiMEidosBlock): no compound statement found for SLiMEidosBlock.

However, hitting OK and then hitting recycle again without changing anything produces no error and the simulation runs just fine.

This seems to consistently happen whenever I change a block whose tick specification. Sometimes the error is shown A LOT, for instance:

Running these scripts on the command line works fine; this is only in the GUI. I'm using GUI version 5.3, Qt 5.15.13, Git-SHA-1 f872f3d.

[bhaller]

Wow, that's a weird one. Reproduces for me, in SLiMgui only (not in SLiMguiLegacy). I take it this is not blocking you in any way? If so, I'm gonna ignore it for a while, as I'm deep in the multi-chromosome weeds...

[petrelharp]

Not blocking, it's just weird.