If you’ve been trying to compile new documents over the past few days, you may have run into problems because purl.org, the front-line service that redirects requests for the “default” Tectonic bundle, has an expired SSL certificate. This is a little frustrating since the whole point of purl.org is to do that one job with rock-solid reliability. But, here we are.
Fortunately (sort of), there is a workaround available, already documented here.
I have contacted the archive.org people, who are in charge of purl.org; hopefully this situation will be ironed out soon. It may be worth investigating alternatives — the purl.org domain is one that is embedded in the distributed binaries, so I want it to point to something that can be expected to work reliably into the indefinite future.