my circumstances dictate that I try to build ClojureScript (and its output) with the master Closure jscompiler rather than the aging 201903 release version pinned by CLJS. I think it's mostly compatible but there's at least one case where ClojureScript depends on a few parts of the com.google.javascript.jscomp API (eg. `AnonymousFunctionNamingPolicy`) that have been removed recently. in 20200920 for that enum specifically, not sure if there are other breaking changes. is there a nightly or prerelease version of CLJS out there that works with the latest Closure compiler? failing that, would patches to update to targeting the latest jscompiler be welcome? I think they'll be a pretty light touch.

I don't think that has been adressed in any patch. you can likely take the cljs/closure.clj file and copy/modify it on your classpath as a quickfix

patch would be welcome too I guess