Re: Failed to compile the emacs latest git master version on Ubuntu 20.10.

[Gregory Heytings]

Then I'd suggest to use --without-m17n-flt as Eli says.  It seems however 
that HarfBuzz and m17n are not incompatible, on my computer configure 
outputs:

  Does Emacs use HarfBuzz?                                yes
  Does Emacs use -lm17n-flt?                              yes

FWIW, I just compiled the lastest master (004d7e97e2) and have the same 
libraries installed:

ii libm17n-0:amd64   1.8.0-2
ii libm17n-dev:amd64 1.8.0-2
ii libthai-data      0.1.28-3
ii libthai-dev:amd64 0.1.28-3
ii libthai0:amd64    0.1.28-3

Are the libthai-data and libthai-dev:amd64 packages installed on your 
machine?