tlmgr-candidates

List all available repositories from which a package can be installed

$ tlmgr candidates [package]

Note:
"tlmgr-candidates" is not a direct executable command.
It refers to the concept of packages eligible for update within the TeX Live ecosystem.
To interact with update candidates, you typically use the following tlmgr commands:

tlmgr update --list
tlmgr update --dry-run
tlmgr update [package...]

--list
    Lists all packages that are identified as update candidates by tlmgr without performing any actual updates. This shows the packages along with their current and available versions.

--dry-run
    Performs a simulation of the update process, showing which packages would be updated, installed, or removed, and resolving dependencies. Similar to --list but provides more detailed action plans.

--all
    When used with tlmgr update, this option instructs tlmgr to update all identified candidates (all packages for which a newer version is available in the repository).

--self
    Updates tlmgr itself, which is often treated as a special candidate due to its role in managing the TeX Live installation.

--repository URL
    Specifies an alternative repository URL from which to check for update candidates. This allows checking for updates from a specific mirror or a local repository.

--force
    Overrides some checks or warnings, potentially forcing an update even if tlmgr has concerns about the candidate.

"tlmgr-candidates" is not a direct executable command in Linux. Instead, it refers to the crucial internal process and criteria used by tlmgr (the TeX Live Manager) to identify packages that are eligible for an update. When a user initiates an update operation, for example with tlmgr update, the first step involves tlmgr querying its configured TeX Live repositories to determine if newer versions of currently installed packages exist. These identified packages, which have a more recent version available remotely, are termed "update candidates." The process involves a sophisticated comparison of version numbers, dependencies, and sometimes even checksums between the locally installed package and the remote offering. Factors such as the current TeX Live release (e.g., TL2023, TL2024) and the specific repository mirror chosen (e.g., a CTAN mirror) directly influence which packages appear as candidates. Users do not execute "tlmgr-candidates" directly; rather, they interact with this concept by using tlmgr's update-related subcommands. For instance, tlmgr update --list or tlmgr update --dry-run are commands that will explicitly show the list of packages that tlmgr considers to be update candidates, along with their current and proposed versions. This mechanism is fundamental to maintaining a secure, stable, and up-to-date TeX Live environment, ensuring access to the latest features, bug fixes, and compatibility improvements for all TeX/LaTeX-related components.

As "tlmgr-candidates" is not a standalone command, its behavior is entirely dependent on the tlmgr utility. It requires an active internet connection to query remote TeX Live repositories for available updates. The specific set of update candidates presented will vary based on the configured TeX Live release (e.g., TL2023, TL2024) and the chosen repository mirror, as different mirrors might synchronize at different times or host different versions. Care should be taken when updating, especially with pre-release or development versions of TeX Live, as updates might introduce instabilities.

When tlmgr update is invoked, tlmgr compares the version numbers of locally installed packages against the latest versions listed in the TeX Live repository's database. If the remote version is newer, the package is flagged as an update candidate. This process also considers dependencies, ensuring that all necessary packages are present or updated for a successful installation.

The specific TeX Live repository (mirror) configured for tlmgr directly influences the list of update candidates. Different mirrors might be synchronized at varying times, or during a release cycle, they might host different stages of development. Using a consistent and up-to-date mirror is crucial for getting the expected set of candidates and avoiding issues.

The concept of managing update candidates has been integral to TeX Live's package management system since the introduction of tlmgr (TeX Live Manager). tlmgr replaced older, less sophisticated update mechanisms, providing a robust, internet-enabled way to keep TeX Live installations current. The logic for identifying and presenting update candidates has evolved with improvements in repository synchronization protocols, dependency resolution algorithms, and the increasing complexity of the TeX Live distribution itself. This continuous development ensures that users can reliably update their TeX distributions with the latest bug fixes and package versions.

tlmgr(1), tlmgr update(1), tlmgr install(1), tlmgr remove(1)