GYES, a multifibre spectrograph for the CFHT by Bonifacio, P, Mignot, S, Dournaux, J, François, P, Caffau, E, Royer, F, Babusiaux, C, Arenou, F, Balkowski, C, Bienaymé, O, Briot, D, Carlberg, R, Cohen, M, Dalton, G, Famaey, B, Fasola, G, Frémat, Y, Gómez, A, Haywood, M, Hill, V, Huet, J, Katz, D, Horville, D, Kudritzky, R, Lallement, R