Setting the import directory to a path that already contains photos may fail silently, with Shotwell setting it back either to ~/Pictures or to (None).
Note that this happened to me after I deleted ~/.shotwell. My (very uneducated) guess is that the program may need to keep the files in the import directory in sync with the data in ~/.shotwell, ignoring the import-dir setting if that's not possible.
So, I guess this bug should be summed up as:
Setting the import directory to a path that already contains photos may fail silently, with Shotwell setting it back either to ~/Pictures or to (None).
Note that this happened to me after I deleted ~/.shotwell. My (very uneducated) guess is that the program may need to keep the files in the import directory in sync with the data in ~/.shotwell, ignoring the import-dir setting if that's not possible.