Leroy Tennison writes:
I am going to take a really wild guess and say "Try replacing the outermost quotes with single quotes or escape the double quotes around the numeral 1". Your second example has double quotes within double quotes and I'm wondering if that's getting rendered as "yum --debuglevel=" 1 " install ..." (extra space added for emphasis).
The outermost quotes are not part of the command, they were only a means to set off the command typed from the surrounding text.
Single quotes around the option arg don't work either.