Fix nix help shell by properly handling command aliases (backport #13496)#13500
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Mic92 merged 1 commit into2.30-maintenancefrom Jul 17, 2025
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Previously, `nix help shell` failed with "Nix has no subcommand 'shell'" despite `nix shell --help` working correctly. This happened because the `shell` command is actually an alias for `env shell`, and the help system wasn't resolving aliases when looking up documentation. This patch modifies the `showHelp` function to check for and resolve aliases before generating the manpage name, ensuring that shorthand commands like `shell` get proper help documentation. Closes: #13431 (cherry picked from commit d678b07)
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This pull request has been removed from the queue for the following reason: Pull request #13500 has been dequeued. The pull request could not be merged. This could be related to an activated branch protection or ruleset rule that prevents us from merging. (details: Required status check "installer test on macos" is queued.). You should look at the reason for the failure and decide if the pull request needs to be fixed or if you want to requeue it. |
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Fix
nix help shellby properly handling command aliasesCloses: #13431
Problem
The
nix help shellcommand incorrectly fails withNix has no subcommand 'shell'despitenix shell --helpworking correctly. This happens becauseshellis actually an alias forenv shell, and the help system wasn't resolving these aliases when looking up documentation.This creates a confusing user experience where the shell command both exists and doesn't exist depending on how users try to access its documentation.
Solution
This PR modifies the
showHelpfunction insrc/nix/main.ccto check for and resolve aliases before generating the manpage name. When a user requests help for an aliased command likeshell, the system now correctly looks up the documentation for the actual command (env shell).The implementation is straightforward - it adds a few lines to the
showHelpfunction to check if the requested subcommand matches any aliases in thetoplevel.aliasesmap, and if so, replaces the subcommand with the actual command path before generating the manpage name.This is an automatic backport of pull request #13496 done by Mergify.