The FileTypeDetectors based on libgio and libmagic introduce a certain unpredictability in the results of file probing. Also, testing on a minimal Ubuntu 16.04 x64 desktop system showed that while these detectors correctly identified an HTML file as text/html, they did not identify any of the common types "image/jpeg", "audio/mpeg", "video/mp4", "application/pdf", nor "image/png" for files of these respective types whereas the detector based on /etc/mime.types did correctly identify them. Given this apparent lack of adding value, removing these detectors would likely have little impact, would improve predictability of the results, and would make probing on Linux and Solaris equivalent, i.e., based on ~/.mime.types and /etc/mime.types alone.