I try to buy my clothes from shops that sell to the trades/safety gear (e.g. brands like "Hard Yakka", although I guess that brand probably doesn't exist outside of Australasia). Most of these shops do a good line of cargo pants/shorts.

But where does one get jeans that were made of the non-stretch denim that we use to get in the 1980s? That stuff was as thick as a tarpaulin (for those of us who are younger, tarpaulins used to be made of fabric, not plastic).