1. ... c5 is inaccurate??

I recently submitted a Sicilian game I lost as black for computer analysis here on chess.com and I just realized that the computer is saying that c5 is an inaccurate response to 1. e4. How can that be? Is the chess engine faulty?

ya chess.com engine sucks.... 

True, chess engine(s) are faulty and naughty in openings.  Kidding a bit, but it's true that sometimes it gives wrong evaluation of the game, or some wrong mistakes, especially in the openings. However, 1...c5 is totally correct and acceptable. 

The chess.com computer has completely refuted the Sicilian ages ago. Then it started demolishing the Caro-Kann. I expect it to completely solve chess by the end of the year.

haha

I see now that this is a well-documented issue. I'll be interested to find out how it solves chess so I can start playing that line in every game.

Thanks!

It may be more accurate to look at the opening database with Sicillian getting a 62.4% sucess rate (win/draw) against white.