What changed between GHC 8.8 and 8.10 that could cause this?

[ÉRDI Gergő]

Hi,

I'm trying to figure out a Clash  problem and managed to track it down to 
a GHC upgrade; specifically, a given Clash version, when based on GHC 
8.8, has no problem synthesizing one module after another from one 
process; but the same Clash version with GHC 8.10 fails with link-time 
errors on the second compilation.

The details are at https://github.com/clash-lang/clash-compiler/issues/1686
but for now I'm just hoping that some lightbulb will go off for someone if 
some handling of internal state has changed in GHC that could mean that 
the symbol tables of loaded modules could persist between GHC invocations 
from the same process.

So, does this ring a bell for anyone?

Thanks,
 	Gergo