Possible dependency issue in makefile

Hi all,
I am building libecpg 13.1 but 13.3 behaves in the same manner and my build
fails with:

path.c: In function 'get_html_path':
path.c:787:38: error: 'HTMLDIR' undeclared (first use in this function)
787 | make_relative_path(ret_path, HTMLDIR, PGBINDIR, my_exec_path);
| ^~~~~~~
path.c:787:38: note: each undeclared identifier is reported only once
for each function it appears in
path.c: In function 'get_man_path':
path.c:796:38: error: 'MANDIR' undeclared (first use in this
function); did you mean 'MAXDIM'?
796 | make_relative_path(ret_path, MANDIR, PGBINDIR, my_exec_path);
| ^~~~~~
| MAXDIM
make[2]: *** [<builtin>: path.o] Error 1

It looks like some dependency issue, because this error is followed by:
make[2]: Entering directory '/builddir/build/BUILD/postgresql-13.1/src/port'
echo "#define PGBINDIR \"/usr/bin\"" >pg_config_paths.h
echo "#define PGSHAREDIR \"/usr/share/pgsql\"" >>pg_config_paths.h
echo "#define SYSCONFDIR \"/etc\"" >>pg_config_paths.h
echo "#define INCLUDEDIR \"/usr/include\"" >>pg_config_paths.h
echo "#define PKGINCLUDEDIR \"/usr/include/pgsql\"" >>pg_config_paths.h
echo "#define INCLUDEDIRSERVER \"/usr/include/pgsql/server\""
>>pg_config_paths.h
echo "#define LIBDIR \"/usr/lib64\"" >>pg_config_paths.h
echo "#define PKGLIBDIR \"/usr/lib64/pgsql\"" >>pg_config_paths.h
echo "#define LOCALEDIR \"/usr/share/locale\"" >>pg_config_paths.h
echo "#define DOCDIR \"/usr/share/doc//pgsql\"" >>pg_config_paths.h
echo "#define HTMLDIR \"/usr/share/doc//pgsql\"" >>pg_config_paths.h
echo "#define MANDIR \"/usr/share/man\"" >>pg_config_paths.h
make[2]: Leaving directory '/builddir/build/BUILD/postgresql-13.1/src/port'

So from my point of view, pg_config_paths.h header file finished
*after* it was used to compile code.

This issue is probably caused by parallel build because sometimes build succeed.

Complete build log: log <https://fjanus.fedorapeople.org/postgresql/build.log>

Regards,

-Filip-