I was tearing my hair out over this, and having done this so many times, forgot a simple rule - it seems like these files, or something I’m using, restricts the column size to around 70ish columns. Go beyond that, and you start getting lots of cryptic errors like no main class found or your external JAR’s not loading (even though the file looks perfectly fine!). Is there really a column cap for these kinds of files?
yes, 72 utf8 characters.
Longer lines are handled by wrapping them, and with a space preceeding the follow-on line.
http://wiki.smartfrog.org/wiki/display/sf/Pattern+-+MANIFEST.MF