For my notes, iftex.sty is in texlive-generic-extra on my system. I did the most recent build for sid in a chroot including the arch all packages, so it's more likely to be something changing than a then-missing-build-dep-indep, but I'll take a look while at Debconf.
- Bug#828946: krb5: FTBFS in testing (LaTeX Error: File `iftex... Santiago Vila
- Bug#828946: krb5: FTBFS in testing (LaTeX Error: File `... Sam Hartman
- Bug#828946: krb5: FTBFS in testing (LaTeX Error: Fi... Santiago Vila