These are some I found in my search history, where I then switched to !g. Not sure if all these examples still fail to produce results with the matching string (but they still seem to have issues, upon a quick glance):

"packages not in the aur"

rake "invalid session id"

"pacman -Qm"

arch "The pgAdmin 4 server could not be contacted"

"previous definition of HTML_NAMESPACE was here"

illustrator "print preview" is darker

systemd Loaded: bad-setting "has a bad unit file setting"