Well, from reading gnome-desktop-thumbnail-script.c I understand thumbnailer does not have access to /usr/local, so changed raw.thumbnailer content to:
[Thumbnailer Entry] Exec=/usr/bin/ufraw-batch --embedded-image --out-type=png --size=%s %u --overwrite --silent --output=%o MimeType=image/x-canon-cr2;image/x-cr2;
Now it works.
Well, from reading gnome-desktop- thumbnail- script. c I understand thumbnailer does not have access to /usr/local, so changed raw.thumbnailer content to:
[Thumbnailer Entry] bin/ufraw- batch --embedded-image --out-type=png --size=%s %u --overwrite --silent --output=%o image/x- canon-cr2; image/x- cr2;
Exec=/usr/
MimeType=
Now it works.