On my slow, x86 Linux box, I noticed an objectionable screen flash with the new build. It looks like Flutter isn't double-buffering properly. I wouldn't be at all surprised if this isn't visible on more capable platforms, but I don't have an easy way to find out. I wasn't able to find a bug in the Flutter issues list on Github, but I have seen recent reports of this issue on Stackexchange. This doesn't happen when using the core calculator - i see it e.g. when the cursor goes over the menu area, causing the menu highlight to repaint.

Due tho this pub, I'll make 2.1.18 a beta-only release on Linux. I'll try to check back to see if Google has managed to fix this issue.