Sorry, hit Enter before adding a bug description ... I had the httpd-2.0.50 sources in my home directory. This home directory is in /home/sag, which is in fact a symbolic link to /export/spare2/sag. As a consequence, the generated file servers/export_files contained all *.h files twice: Once with /home/sag, and once with /export/spare2/sag as a prefix. In the following process, the awk script added a lot of functions twice to exports.c and compilation failed.
*** This bug has been marked as a duplicate of 8867 ***