An expression like self.spec.find_tag('!BuildRequires') is supposed to return a list of dependencies. However, if the dependency contains spaces, it's returned as a list of chunks, separated on space.

Happens e. g. when parsing the standard perl dependency
{{{
Requires: perl(:MODULE_COMPAT_%(eval "%{__perl} -V:version"; echo $version))
}}}
returning a list of five chunks.

Generally, this is not that easy. Dependencies are separated by ',' and newlines, but a ',' in a quoted string or within parenthesis should not split. Practically, splitting on ',' is still much better than current algorithm.