Option 1... get the Canon EF 50/1.4... it's a good lens and with a few simple precautions will likely give you long, reliable service. First, get the matched lens hood and use it. That helps protect the front barrel of the lens from bumps while using the lens, and when storing the lens, the hood reversed covers and protects the focus ring. Secons, it's also a good idea with this lens (actually with most lenses) to set it to infinity when storing it, to fully retract the front barrel. Third, don't make a habit of overriding focus manually a lot, without turning off AF. Even tho this is a USM lens, some think that treating it like one and using FTM a lot might cause faster wear and tear on the mechanism. Finally, don't drop it.
My 50/1.4 has been fine for at least eight or ten years regular use. I bought it used so am not sure how old it really is. It came with and I've always used it with the hood. Never gave it any special care, just what's noted above, which are things I'd consider reasonable and practical with any lens. Yes, some simply break unexplicably... but usually if that happens it's within the first year warranty period.
Option 2... Sigma 50/1.4... Seems better built than the Canon, but it's a much newer lens without nearly the history fo the Canon, and I'm sure hasn't seen nearly as many copies sold and in use. So, who can say for certain if it's actually going to be more durable in the long run. Bigger and heavier (a lot bigger and heavier, who ever heard of a 50mm lens needing a 77mm filter?) doesn't necessarily equate to "better built/more durable".
It is almost certain that you will need to swap the Sigma with the retailer until you get a "good copy" that's well calibrated... Or will need to send the lens in to Sigma under warranty to have it calibrated. This is all too common with Sigma. But once calibrated, it should be fine.
Differences between the two...
The Canon doesn't come with a lens hood... it's sold separately. The Sigma includes a hood.
The Sigma is a little more expensive and a whole lot bigger and heavier.
In terms of image quality, the Sigma is typically a little sharper wide open at f1.4, the two are about equal from around f2.2 to about f5.6, after which the Canon is generally sharper. The color rendition of the Sigma seems a little cooler. The Canon has an 8-bladed aperture and the Sigma's is 9-bladed. That makes the Sigma's aperture slightly more perfectly round at any setting other than wide open, so that it renders slightly smoother background blur. Still, both of them are excellent in this respect and there's not really a whole lot of difference... You need to spend a lot more for the 50/1.2L or a Zeiss ZE 50/1.4 (manual focus only) for any smoother background blur... Compared to the cheaper Canon EF 50/1.8 (5-bladed aperture), both the Sigma and Canon 50/1.4 are more flare resistance, render richer & more saturated color, offer better contrast, smoother backgrounds, have faster & more accurate AF, and are better built/more durable.
There really is no such thing as a "perfect" lens. Optics always involve some compromise. A large aperture lens that renders shallow depth of field puts extra demands on focus accuracy (and today's cameras aren't very manual focus friendly). It's always a balancing act, price vs build quality, sharpness vs chromatic aberration, etc., etc.
Over the years, Lensrentals.com has periodically shared their lens repair rates with a lot of popular lenses. This might give us a bit of a guide, since they often have dozens of copies of any given model and properly inspect them before and after each use. Their data showed around a 20% failure rate with the Canon lens... Lensrentals also has reported a lot of problems with Sigma lenses, in general... enough so that they discontinued carrying them for a few years (but now do stock them again). But it's important to keep in mind that this is likely a "worst case" scenario. After all, those rental lenses probably spend more time bouncing around in the back of a UPS truck than shooting photos... And likely they are often used by people who don't give them any particular care. I dunno if Lensrentals sends the Canon 50mm out with a hood or not (I'd bet not, since it's sold separately).
There is no clear cut "winner"... I'd just suggest get the lens that seems to meet your budget and needs best and start shooting... Use reasonable precautions and you will probably be fine. If something breaks or needs calibration, hopefully it will be within the warranty period. If not, well it's still not the end of the world... I've heard the Canon costs about $130 US to repair the AF. But mine has been fine for many years and never required repair or calibration (knock on wood!)