> In Library/Formula/openfst.rb:
> 
> >      system "./configure", "--disable-dependency-tracking",
> > +                          "--enable-far", "--enable-pdt",
> 
> Style nit-pick: we prefer to keep --prefix... near the top of the options, so add these two new ones under that (and preferably each on a separate line.)

@adamv: done

> You can use ENV.libstdcxx to force it to use libstdc++ with clang.

@mistydemeo: just did this using the one-liner you suggest in #24545

Tested these two changes together and they work on my system.