Bibliography

LaTeX documents that use \cite{} need a bibliography processor. Modern documents almost always want biblatex + biber, which handle Unicode, sophisticated styles, and multi-bibliography workflows correctly.

rules_latex ships a vendored biber binary alongside the tectonic toolchain. To use it, set biber = True on your document.

Minimal example

% paper.tex
\documentclass{article}
\usepackage[backend=biber,style=numeric]{biblatex}
\addbibresource{references.bib}

\begin{document}
This sentence cites Knuth~\cite{knuth1984}.
\printbibliography
\end{document}

% references.bib
@book{knuth1984,
  author = {Donald E. Knuth},
  title  = {The {{\TeX}}book},
  publisher = {Addison-Wesley},
  year = {1984},
}

# BUILD.bazel
load("@rules_latex//latex:defs.bzl", "latex_document")

latex_document(
    name = "paper",
    main = "paper.tex",
    srcs = ["paper.tex", "references.bib"],
    biber = True,
)

bazel build //:paper

The build runs tectonic, biber, tectonic again — all sandboxed, all hermetic. The resulting PDF has resolved citations.

How it works

When biber = True:

1. The platform-specific biber binary from the toolchain is staged into a per-action scratch directory.
2. That directory is prepended to PATH inside the sandbox.
3. Tectonic's biblatex subprocess resolves biber by basename and shells out to it as usual.

The biber binary is vendored from a GitHub release mirror on the rules_latex repo, content-addressed by SHA-256. See DESIGN.md §4.9 for the full implementation details.

Version coupling

Biber is tightly coupled to biblatex's "control file format" version. rules_latex pins biber 2.17 to match the biblatex 3.17 shipped in the upstream Tectonic bundle. You can't use a newer biber with the default bundle. If you specifically need biblatex 3.18+ features, self-host a newer bundle (see the bundle staleness discussion).

Platform support

Platform	Toolchain biber?	Note
Linux x86_64		Upstream prebuilt
Linux aarch64		Use biber_strategy = "system"
macOS x86_64		Universal binary
macOS aarch64		Universal binary
Windows x86_64

Linux arm64 workaround

The upstream biber project doesn't ship a Linux arm64 binary, so the toolchain has a gap there. Install biber via your distro (apt-get install biber) and set:

latex_document(
    name = "thesis",
    main = "thesis.tex",
    srcs = [...],
    biber = True,
    biber_strategy = "system",   # use system biber on PATH
)

This is less hermetic — your build depends on whatever biber is installed — but it's the only option until v0.3 ships a built-from- source biber for that platform.