Topic: ImageMagick6 rpm spec cannot actually disable webp, jbig, etc.
The ImageMagick6 rpm spec checks "with_webp" to set "--with-webp", "with_jbig" to set "--with_jbig", etc. But these options are on by default already, and so they're effectively useless. They really need to be turned off explicitly when "!with_webp". Running `./configure --help` also shows that the only valid option is "--without-webp", not "--with-webp". So the rpm spec should really be written so that if "with_webp" is not true, then "--without-webp" should be set. Currently as the rpm spec is written, it's impossible to explicitly turn off webp, jbig, etc.
I have not checked all the other configure flags, so it'd be good to audit those too.