tectonic 0.8.0

tectonic 0.8.0 (2021-10-11)

This release fixes a showstopping issue introduced by recent changes to the
archive.org PURL (persistent URL) service. All users are advised to upgrade
immediately, although it is possible to continue using older releases in some
limited circumstances.

By default, Tectonic downloads (La)TeX resource files from the internet as
needed. Before this release, Tectonic would query a PURL in order to know where
to locate the most recent “bundle” of resource files. On Wednesday,
archive.org updated the implementation of its service in a way that interacted
catastrophically with the way that Tectonic processes URL redirections. The
result was that Tectonic became unable to download any of its resource files,
breaking essential functionality. Thanks to @rikhuijzer for providing early
reporting and diagnosis of the problem.

This release fixes the redirection functionality (#832, @pkgw), but more
importantly it switches from querying archive.org to using a new dedicated
webservice hosted on the domain fullyjustified.net (#833, @pkgw). The
motivation for this switch is that besides this particular incident,
archive.org has had low-level reliability problems in the past, and more
important, it is blocked in China, preventing a potentially large userbase from
trying Tectonic.

The new URL that is queried is:

https://relay.fullyjustified.net/default_bundle.tar

The redirection is implemented with a simple nginx server defined in the new
tectonic-relay-service repo and hosted on Microsoft Azure cloud infrastructure
defined in Terraform configuration in the tectonic-cloud-infra repo. @pkgw owns
the domain name and Azure subscription.

Along with the above change, this release contains the following improvements:

• Add the tectonic -X dump V2 CLI command, which runs a partial document
  build and outputs a requested intermediate file. This can help integrate
  external tools into a Tectonic-based document processing workflow (#810,
  @pkgw)
• Add support for custom support file search directories with the -Z search-path=<path> unstable option (#814, @ralismark)
• Fix the watch V2 CLI command on Windows (#828, @Sinofine)
• Fix repeated updates in the watch V2 CLI command (#807, @jeffa5)
• Fix an incorrect error message when running V2 CLI commands outside of a
  workspace (#813, @ralismark)
• Add a more helpful warning if an input produces empty output (#817,
  @ralismark)
• Prevent an incorrect warning when reading some kinds of EXIF metadata (#822,
  @korrat)
• Reject -Z shell-escape=false, which would be parsed as enabling
  shell-escape (#823, @ratmice)