  We present the first exoplanet atmosphere detection made as part of the
SPIRou Legacy Survey, a Large Observing Program of 300 nights exploiting the
capabilities of SPIRou, the new near-infrared high-resolution (R ~ 70 000)
spectro-polarimeter installed on the Canada-France-Hawaii Telescope (CFHT;
3.6-m). We observed two transits of HD 189733, an extensively studied hot
Jupiter that is known to show prominent water vapor absorption in its
transmission spectrum. When combining the two transits, we successfully detect
the planet's water vapor absorption at 5.9 sigma using a cross-correlation
t-test, or with a Delta BIC >10 using a log-likelihood calculation. Using a
Bayesian retrieval framework assuming a parametrized T-P profile atmosphere
models, we constrain the planet atmosphere parameters, in the region probed by
our transmission spectrum, to the following values: VMR[H2O] =
-4.4^{+0.4}_{-0.4}, and P_cloud >~ 0.2 bar (grey clouds), both of which are
consistent with previous studies of this planet. Our retrieved water volume
mixing ratio is slightly sub-solar although, combining it with the previously
retrieved super-solar CO abundances from other studies would imply super-solar
C/O ratio. We furthermore measure a net blue shift of the planet signal of
-4.62^{+0.46}_{-0.44} km s-1, which is somewhat larger than many previous
measurements and unlikely to result solely from winds in the planet's
atmosphere, although it could possibly be explained by a transit signal
dominated by the trailing limb of the planet. This large blue shift is observed
in all the different detection/retrieval methods that were performed and in
each of the two transits independently.
