For some reason, one of my Linux Mint 18.1 machines was not able to run ispell, which gave this error message:
Can't open /usr/lib/ispell/default.hash
Comparing this installation with another machine running the same OS,
it seemed that the missing file was supposed to be the first in a chain
of symlinks that eventually pointed to
The man page for ispell suggested that the
buildhash program might
possibly create the missing files, but I could find no instructions
online about how to use it.
Eventually I figured out that I needed to install the missing
package, which contains the missing files and runs
buildhash as part
of its configuration script. I’m still not sure why this package wasn’t installed
automatically when the Mint was first installed on this machine.