$ raw-thumbnailer img_4680.cr2 foo.png

***MEMORY-WARNING***: raw-thumbnailer[26094]: GSlice: g_thread_init() must be called before all other GLib functions; memory corruption due to late invocation of g_thread_init() has been detected; this program is likely to crash, leak or unexpectedly abort soon...
** (raw-thumbnailer:26094): DEBUG: file (null) is raw

Segmentation fault (core dumped)