Streamlining Latex Package Updates: Best Practices And Common Pitfalls
Keeping LaTeX Packages Current
The LaTeX ecosystem relies heavily on packages that extend the core LaTeX functionalities. However, with hundreds of packages in existence, keeping them up-to-date can be challenging. Package version incompatibility issues often arise when documents reference older package versions compared to more recent versions installed on the system.
The problem of package version incompatibility
When an older LaTeX document references a package that has since been updated on the system, hard-to-diagnose errors can occur. For example, if version 1.0 of the "graphics" package defined the \includepicture command, but version 2.0 renamed it to \includegraphics, documents written for 1.0 will break if 2.0 is installed. Resolving such incompatibilities often requires tedious troubleshooting to pinpoint the offending packages.
Finding outdated packages with \listfiles
LaTeX provides the \listfiles command to inspect the versions of all packages used in a document during compilation. For example, adding \listfiles to the preamble will output a log of loaded packages and versions after each compile. Developers can scan this list to identify packages that may have newer versions available. However, this approach requires manually checking each package online to locate updates, which does not scale well. Automated tools discussed later can ease this process.
Upgrading packages with LaTeX package managers
LaTeX package managers like tlmgr (TeX Live) and MiKTeX Console provide integrated solutions for managing packages. These tools can download, install, upgrade, and remove packages from the TeX distribution. When invoked with commands like \tlmgr update --all, the manager queries remote repositories for available updates and seamlessly installs any out-of-date packages it finds. This automation takes the manual labor out of locating and upgrading packages. However, it can still fail to resolve certain version mismatch issues, especially with third-party packages not registered to the main TeX repository.
Best practices for package management
While LaTeX package managers automate much of the upgrade process, authors can follow certain best practices to further streamline package updates.
Using version control systems
Version control systems like Git allow tracking entire LaTeX projects including all package files and document sources. Developers can commit the state of the project alongside exact package versions. When incompatible packages break the build later on, Git provides tools like git bisect to efficiently test and locate the problematic commits and packages. Integrating LaTeX projects with Git improves manageability as projects scale in complexity across packages, documents, and authors.
Tracking package versions in document preamble
Even when using automated tools, locking down trusted package versions in the document preamble is advisable. For example, adding lines like \usepackage[version=2.01]{graphics} ensures continue using a specific graphics package version regardless of system changes. This protects against edge cases where managers install unexpected package upgrades. Certain critical packages like geometry, graphics, hyperref may warrant version freezing more than others. But use judiciously to not hinder required upgrades.
Separating third-party packages from custom packages
When working with specialized third-party packages not registered to the main TeX repositories, isolation from in-house custom package development is recommended. Third-party packages often land on arbitrary release cycles, so maintaining custom forks can become demanding. By separating the code bases, custom packages only rely on the vendor's published releases. This way package manager upgrades on custom packages cannot inadvertently destabilize unmaintained third-party dependencies.
Common issues when upgrading packages
While automation, version pinning, and separation of concerns can prevent many issues, edge cases still arise when upgrading LaTeX packages:
Changed or removed commands
LaTeX packages sometimes rename existing commands or remove deprecated functionality across versions. But documents written for older versions still reference the old command names and behaviors. For example, the foo package v1.0 may define \foo, but v2.0 renames this to \foonew. Without updating the documents, such command changes can lead to undefined control sequence errors. Fixing requires edits to swap old commands with new ones across documents and custom package libraries.
Conflicts with other updated packages
Independently upgrading two separate packages can sometimes inadvertently introduce compatibility issues that worked fine previously. For example, if the bar and foo packages both defined \baz functionality with slight behavioral differences, a document could use these interchangeably via \foo_use:baz and \bar_use:baz conditional macros. But if recent bar and foo releases modify the \baz impl such that they now conflict, upgrading both together suddenly breaks. The system dependency graph lacks visibility into such cross-package constraints. Authors must manually tweak custom patches or fork one package locally to resolve such composite version mismatch bugs.
Changes in formatting or output
LaTeX packages also commonly move, rename, or change internal macros that alter the document formatting or output artifacts. For example, the hyperref package could style links to use dark red in older versions but brighter red moving forward. Or the TikZ graphics package may tweaked default node radius padding by 2 pixels. Such incremental changes accumulate over versions and can unintentionally introduce output differences or formatting shifts relative to previous stable releases. Addressing requires comparing rendered document artifacts across package versions to selectively undo or constrain overzealous upgrades.
Troubleshooting package upgrades
When facing compatibility issues from LaTeX package upgrades, authors can leverage the following incremental troubleshooting workflow:
- Isolate problem document and validate intact behavior on last known good version
- Bisect package changes via version control history to identify first broken version
- Scan package release notes on caveats around removed or renamed existing functionality
- Upgrade document to reference new package APIs and commands
- Construct local custom package forks to patch composite version constraint issues
- Override specific packages in preamble to prior known good versions
- Report bugs to package authors detailing version-specific mismatches
While time-consuming, methodically narrowing package changes with test cases and backports can ultimately help resolve compatibility issues from upgrades. Authors can additionally contribute info to latex dev communities on especially subtle or unintended behavioral differences arising across package versions.
Conclusion: Making package updates seamless
Keeping the LaTeX packages powering documents current with latest releases requires vigilance to prevent version mismatches or unintended formatting and output changes across upgrades. Relying solely on automation defaults often proves insufficient as projects scale in complexity across custom packages, third-party integrations, outputs artifacts, and legacy documents written against prior versions. Authors should leverage version pinning, isolation, branching strategies and incremental troubleshooting to smooth package upgrades.
Proactively tracking release notes for potentially breaking command and API changes can also cut down on technical debt when upgrading documents and dependencies. Locking customized documents to trusted versions via preamble overrides offers insurance against inadvertent formatting or output changes across routine package updates. And compartmentalizing third-party packages away from custom developments can eliminate tension pulling in specialized external dependencies. Combining these best practices ensures LaTeX package upgrades enhance rather than hinder document authoring and publishing workflows.
