Currently - the Doxfiles that are checked in, are from (old? nine years
ago), and currently produces warnings when you build things:

warning: Tag 'TCL_SUBST' at line 168 of file './Doxyfile.in' has become obsolete.
         This tag has been removed.
warning: Tag 'COLS_IN_ALPHA_INDEX' at line 871 of file './Doxyfile.in' has become obsolete.
         This tag has been removed.
warning: Tag 'PERL_PATH' at line 1558 of file './Doxyfile.in' has become obsolete.
         This tag has been removed.
warning: Tag 'MSCGEN_PATH' at line 1580 of file './Doxyfile.in' has become obsolete.
         This tag has been removed.

Update to 1.9.1 via:
doxygen -u ./bindings/csharp/Doxyfile.in
doxygen -u ./Doxyfile.in

and check in the difference.
Unfortunately - this has quite a few comment differences :(
 2 files changed, 1885 insertions( ), 374 deletions(-)

but if you only look at the actual options that have been moved/updated,
it's pretty minimal.

git diff | grep -v "\ \#" | grep -v "\-\#" | diffstat
 b/Doxyfile.in               |   10          -
 bindings/csharp/Doxyfile.in |    8         
 2 files changed, 17 insertions( ), 1 deletion(-)

Signed-off-by: Robin Getz <[email protected]>