Samba 4.16 build failures

[Matt Grant]

Hi!

Just trying to compile 4.16.0 for my debian servers as a Debian package,
from debian/rules based on actual Debian packaging.

Keep getting lots of errors about GSSAPI_LIB_FUNCTION not being defined....
4.15.x compiles.

Noticed that heimdal has shifted from source4/heimdal to third_party/heimdal

Could some one please enlighten me about how to get
third_party/heimdal_build/include/gssapi.h to be used for package builds,
with unbundled and bundled libraries?

Thank you!

Matt Grant