On Sat, Jan 25, 2020 at 1:27 AM Marcel Fabian Krüger <tex@2krueger.de> wrote:

would it be possible to pull a new version of luaharfbuzz in before
TeXLive 2020 is frozen? There hasn't been an official release, but there
are some new interfaces which would be very useful for luaotfload.

so sync with master (cuurently 1578746387-e9564d0) 
There are also at least two bugs in HarfBuzz affecting luaotfload for which
the fixes are in the repo but not yet released, but I guess the HarfBuzz
version is controlled by the TeXLive team?