Ok so you asked for advice and no one advised you to get your ductwork cleaned?! Nobody gets their ducts cleaned because they stink only to remove dust. What procedure removes an odor that is deep inside the ductwork?

Have your attic checked for roof rats, a friend of mine had a stink for days before discovering a dead roof rat (palm rat) in the attic.

You can buy an ozone generator on Amazon that does a pretty good job of getting rid of musty odors. Set it to run a couple of hours while you are out of the house. Then air out the house when you return. Repeat the process when needed. We are snowbirds and do this with our house up north. It won't help if you have an open drain, but does help with musty odors. I keep the air conditioner fan running while the ozone generator is on. That way the ducts get "cleaned".

Well wonder what the results will be when his ductwork is cleaned.

Dead bird(s), rats, squirrel, etc.
We had an odor problems in a former home that turned out to be bird nest in the attic during construction.....then after closed in......peeee-yeeew.

Maybe roofers left their lunch cooler in the attic

One other possible culprit could be a blocked plumbing vent line after the new roof install. It would certainly warrent a visual inspection to make sure nothing got covered over thus allowing methane gas to flow into the attic space.

Probably something like this

Up north we had a small animal fall into an interior wall. Since it couldn't get out, it eventually died and we had a terrible smell for a couple of weeks.

It was a frame house and the tops of the walls were not sealed.

We had pest control in and they said that nothing could be done but the odor would go away.

Just trying to understand how that gas will escape from a solid pvc pipe

The pipe may be solid PVC but it has slip joints which are supposed to be glued. However, I had a small wet spot in my ceiling in a former house which turned out to be condensed water from the bath fan vent which was not glued in an almost horizontal run to the roof vent. This house had several vents from plumbing connected to a single roof vent. I believe that it is worthwhile to check the vents since the roofers have to remove old "boots/collars" around the roof vent and install new. If the joints were not glued the vent may have been lifted up and a caused an opening/ vent leak.

I have seen instances where the roofing contractor either dislodged one of the vent pipes or roofed over leaving the open end of the pipe in the attic space.

Unrelated to the OP's post, your post serves as a good reminder for all the people getting new roofs. Make sure any and all vent pipes are connected after the job is done. I've seen more than one house who had a new roof put on, and the roofing company never connected the dryer vent...it was emptying directly in to the attic.