It may actually be a very tiny error in your conky.conf file.
I was plagued by this as well and went into the convert.lua (in 15.10,
it's at /usr/share/doc/conky-std) to see what was going on. The line
above 138 where the configuration file was split in two caught my eye,
because the regular expr
I decided to do a complete reinstall, downloading a new copy of the
Xubuntu image, checking its signature, making a new bootable flash
drive, verifying its integrity.
While the second clean install did eliminate a couple of other weird
issues, the error with conky is still present for me.
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You