Jan,

Thank you for finding that for me.

I will install fontsproto-devel.  Why did yast not show that?

Larry

When I tried that in 15.4 - I got cannot find X11/font/font.h - it was there in Tumbleweed but not in a fresh install of
15.4.
One of my virtual machines running 15.4 that had been 43 > 15.0 >15.1 >15.2 > 15.3 and now 15.4 had all the /usr/lib/X11
files so I rsync them to my 15.4 development machine and Oracle VB build with no errors.
When did the /usr/include/X11 files get removed?  yast could not find them in 15.4.

They were not removed. Just look in the master file catalog for where 
they are.

15.4:

wget http://download.opensuse.org/distribution/leap/15.4/repo/oss/ARCHIVES.gz
gzip -cd ARCHIVES.gz | grep /fonts/font.h
./x86_64/fontsproto-devel-2.1.3-1.22.x86_64.rpm:    
-rw-r--r--    1 root    root                     4214 May 25  2018 /usr/include/X11/fonts/font.h

TW:

wget http://download.opensuse.org/tumbleweed/repo/oss/ARCHIVES.gz
gzip -cd ARCHIVES.gz ..
./x86_64/xorgproto-devel-2022.2-1.3.x86_64.rpm:    
-rw-r--r--    1 root     root                     4253 Aug 31 16:14 /usr/include/X11/fonts/font.h