Hello, I had a problem with configure: I just installed bison 1.28 in a non-standard path using ".\configure --prefix=/my/path/". As I used the bash tab-key-feature (i.e. filename completion) I got the trailing "/" in the path. This caused double "//" to occur in several files (bison.simple, config.h and config.status). Although you might argue that the path given was wrong and so it was my own fault, I think such input should be tolerated and silently corrected by configure. ./configure --version told me "configure generated by autoconf version 2.13". Best regards Martin P.S. I don't know whether this is a list or a single mail account, but if you like to answer please email me directly.