How does Atlas handle Perl module version conflicts?

Atlas executes `cpanm` directly via `bash`, allowing it to observe and report any version conflicts or installation failures just as a human would. You can then guide Atlas to resolve them by adjusting your `cpanfile` or `Makefile.PL`.

Can Atlas fix Perl code that uses `use strict` and `use warnings`?

Yes, Atlas is designed to work within modern Perl best practices. It can identify and fix issues in code using `use strict` and `use warnings`, and can even add them to legacy scripts if requested, ensuring robust code quality.

How does Atlas know which Perl files to modify?

Atlas reads the output from `prove (Test2::V0)` and compiler errors, which typically point to specific `.pm` files and line numbers. It then uses its `edit` tool to make targeted changes, often inspecting new signatures with `lsp`.

Does Atlas support custom Perl test runners or just `prove`?

While Atlas explicitly supports `prove (Test2::V0)`, its `bash` tool allows it to execute any custom Perl test runner or script you specify. Atlas will then parse the output to identify failures, adapting to your specific testing setup.

How does Atlas ensure my Perl code style is maintained?

Atlas integrates with `perltidy`. After making changes, it can run `perltidy` on modified files, respecting your `.perltidyrc` configuration. This ensures all automated fixes adhere to your team's established Perl coding standards.

Can Atlas rollback changes if a Perl upgrade goes wrong?

Yes. Atlas snapshots file changes as git patches before writing them. If an upgrade introduces unforeseen issues, you can easily use standard git commands to revert the changes, or leverage Atlas's ability to roll back edits.

Is my Perl code sent to external servers for analysis?

Atlas can build its code index with local Ollama embeddings, keeping your Perl code off third-party servers. Every Atlas tool call is also permission-gated, giving you full control over what actions are taken and where your code interacts.

Upgrade a dependency and fix the breakage in Perl with Atlas in 2026

Atlas empowers Perl developers in 2026 to upgrade dependencies and fix resulting breakage by driving `cpanm` for package management, interpreting `prove (Test2::V0)` output, and applying fixes with `edit` and `lsp` tools, ensuring your codebase remains robust and up-to-date.

How does Atlas upgrade Perl modules with `cpanm`?

Atlas streamlines Perl dependency upgrades in 2026 by directly invoking `cpanm` through its `bash` tool. This ensures that your `cpanfile` or `Makefile.PL` dependencies are updated precisely as you would manually, capturing all output for review, even if it exceeds typical terminal limits.

When you initiate a dependency upgrade, Atlas uses its `bash` tool to execute `cpanm` commands, such as `cpanm --installdeps .` for your `cpanfile` or `Makefile.PL` based distribution, or `cpanm Some::Module@^2.0` for a specific module. This direct interaction with the Perl package manager ensures that the upgrade process mirrors your existing workflow. Atlas captures the complete output from `cpanm`, including any installation errors or warnings, which can be critical for diagnosing issues. If the output is extensive, exceeding typical terminal buffer limits, Atlas automatically saves it to a file, which you can then review using the `read` tool. This comprehensive capture ensures that no detail of the upgrade process is missed, providing a solid foundation for subsequent breakage resolution in your Perl codebase.

How does Atlas identify and fix Perl compile and test failures?

Atlas identifies and resolves Perl breakage by running your `prove (Test2::V0)` test suite via `bash`, then analyzing the TAP output for failures. It uses the `edit` tool to modify `.pm` modules and `lsp` to inspect new function signatures, ensuring fixes are accurate and targeted to the 2026 Perl ecosystem.

After an upgrade, Atlas systematically identifies and addresses any resulting breakage. It begins by running your Perl test suite using `bash -c 'prove -lr t/'`, which executes all `Test2::V0` based tests under your `t/` directory. Atlas then parses the TAP (Test Anything Protocol) output to pinpoint specific test failures. For each failure, Atlas employs its `edit` tool to modify the relevant `.pm` module files. To ensure accurate fixes, especially when dealing with new major versions, Atlas leverages the `lsp` (Language Server Protocol) tool's `goToDefinition` operation. This allows it to inspect the updated function signatures and `@EXPORT` lists within the newly upgraded package, guiding precise code adjustments. This iterative process of running tests, identifying errors, and applying targeted fixes continues until your entire Perl test suite passes cleanly, ensuring a stable migration.

How does Atlas use release notes for Perl dependency upgrades?

When upgrading a Perl module to a new major version, understanding breaking changes is crucial. Atlas employs its `webfetch` tool to retrieve the library's release notes or changelog, providing the agent with the exact context needed to apply 100% accurate fixes, rather than guessing at API changes in 2026.

Upgrading a Perl dependency to a new major version often involves navigating significant API changes. Atlas addresses this challenge by using its `webfetch` tool to retrieve the official release notes, changelog, or migration guide for the upgraded library. For instance, if `Some::Module` is bumped from version 1.x to 2.x, Atlas can fetch the `Some::Module` 2.0 release notes from CPAN or the project's repository. This crucial context informs Atlas about specific breaking changes, deprecated functions, or new required parameters. By having this information readily available, Atlas can apply fixes with its `edit` tool that directly correspond to the actual breaking changes, rather than making educated guesses. This approach significantly reduces the time and effort required to adapt your Perl codebase to new library versions, ensuring the fixes are both correct and efficient.

How does Atlas ensure safe Perl code changes and formatting?

Atlas prioritizes safety and code quality in Perl migrations. After fixing all breakage, it runs `perltidy` on changed files to match your `.perltidyrc` configuration, then presents a unified diff for your approval. This ensures every change, from a single line to 100s of lines, is transparent before committing to git.

Maintaining code quality and consistency is paramount during any migration. Once Atlas has resolved all compile and test failures in your Perl codebase, it takes an additional step to ensure your code adheres to established style guidelines. Atlas will run `perltidy` on all modified `.pm` files. This command automatically formats your Perl code according to the rules defined in your `.perltidyrc` configuration file, ensuring that the diff reflects only functional changes and not stylistic deviations. Before any changes are permanently applied, Atlas computes a unified diff for every file edit and presents it to you for explicit approval. This transparent review process allows you to inspect every line of code Atlas proposes to change, from a single character adjustment to hundreds of lines, giving you complete control. Upon your approval, Atlas can then stage and create commits on your behalf, integrating direct with your git workflow and even snapshotting changes as git patches for easy rollback.

Step by step

01Initiate the dependency upgrade by asking Atlas to execute `cpanm --installdeps .` or `cpanm Some::Module@^2.0` via its `bash` tool, capturing the full output.
02Instruct Atlas to use `webfetch` to retrieve the new major version's release notes or changelog, providing context for breaking changes.
03Ask Atlas to run your test suite with `bash -c 'prove -lr t/'` and analyze the `Test2::V0` TAP output for failures.
04For each identified failure, direct Atlas to use its `edit` tool to modify the relevant `.pm` module, leveraging `lsp`'s `goToDefinition` to inspect new function signatures.
05Repeat running `prove -lr t/` and fixing errors until the entire test suite passes cleanly.
06Have Atlas run `perltidy` on all modified `.pm` files to ensure they conform to your `.perltidyrc` standards.
07Review the unified diff presented by Atlas, then approve the changes for staging and committing to your git repository.

Frequently asked questions

How does Atlas handle Perl module version conflicts?: Atlas executes `cpanm` directly via `bash`, allowing it to observe and report any version conflicts or installation failures just as a human would. You can then guide Atlas to resolve them by adjusting your `cpanfile` or `Makefile.PL`.
Can Atlas fix Perl code that uses `use strict` and `use warnings`?: Yes, Atlas is designed to work within modern Perl best practices. It can identify and fix issues in code using `use strict` and `use warnings`, and can even add them to legacy scripts if requested, ensuring robust code quality.
How does Atlas know which Perl files to modify?: Atlas reads the output from `prove (Test2::V0)` and compiler errors, which typically point to specific `.pm` files and line numbers. It then uses its `edit` tool to make targeted changes, often inspecting new signatures with `lsp`.
Does Atlas support custom Perl test runners or just `prove`?: While Atlas explicitly supports `prove (Test2::V0)`, its `bash` tool allows it to execute any custom Perl test runner or script you specify. Atlas will then parse the output to identify failures, adapting to your specific testing setup.
How does Atlas ensure my Perl code style is maintained?: Atlas integrates with `perltidy`. After making changes, it can run `perltidy` on modified files, respecting your `.perltidyrc` configuration. This ensures all automated fixes adhere to your team's established Perl coding standards.
Can Atlas rollback changes if a Perl upgrade goes wrong?: Yes. Atlas snapshots file changes as git patches before writing them. If an upgrade introduces unforeseen issues, you can easily use standard git commands to revert the changes, or leverage Atlas's ability to roll back edits.
Is my Perl code sent to external servers for analysis?: Atlas can build its code index with local Ollama embeddings, keeping your Perl code off third-party servers. Every Atlas tool call is also permission-gated, giving you full control over what actions are taken and where your code interacts.

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