Summary of Changes

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This pull request addresses a critical issue where installing tools with the --system flag prevented the correct rebuilding of runtime symlinks. Previously, the system would incorrectly default to the user's installation directory, leading to failures. The changes introduce explicit tracking of the installation path within the tool's state and ensure this path is correctly propagated and used during the backend argument resolution process, thereby resolving the symlink rebuilding problem for shared tools.

Highlights

• Enhanced Install State Tracking: The InstallStateTool struct now includes an installs_path field, allowing it to correctly store the installation directory for tools, especially those installed with --system.
• Corrected Backend Argument Resolution: The BackendArg conversion from InstallStateTool has been updated to utilize the newly tracked installs_path, ensuring that runtime symlinks for shared tools are rebuilt using the correct directory instead of defaulting to the user's directory.

Greptile Summary

This PR fixes a bug where installing a tool with --system (shared install directory) would fail during runtime-symlink rebuilding because the resulting BackendArg always used the default user-level dirs::INSTALLS path instead of the actual shared install path.

The fix introduces an installs_path: Option<PathBuf> field to InstallStateTool, populated with the real on-disk directory during both the user-level and shared-level scan passes in init_tools. In From<InstallStateTool> for BackendArg, the stored path is then used to override the default that new_raw would otherwise produce.

Key observations:

• The logic correctly preserves user-dir precedence: for tools present in both the user dir and a shared dir, installs_path points to the user-level directory (the shared scan's or_insert_with closure is skipped for already-seen tools).
• Plugin-only entries (no on-disk installs) deliberately receive installs_path: None, causing BackendArg to retain its default user path, which is the expected behavior.
• cache_path and downloads_path in BackendArg are still derived from dirs::CACHE / dirs::DOWNLOADS regardless of the shared install root (flagged separately in a prior thread).
• No unit test covers the new installs_path override in From<InstallStateTool> for BackendArg, leaving a gap that could silently regress.

Confidence Score: 4/5

• This PR is safe to merge; it fixes a targeted regression for shared/system installs with no impact on the existing user-level install flow.
• The change is minimal and surgical — one new optional field on InstallStateTool and a one-line override in From<InstallStateTool> for BackendArg. The user-level path is unaffected (the stored path equals the default for user-level tools, so the override is a no-op there). The only gap is the absence of a regression test for the shared-path override path, which is why the score is 4 rather than 5.
• No files require special attention; both changed files are small and well-scoped.

Important Files Changed

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[init_tools scans install dirs] --> B{User-level dir?}
    B -- yes --> C[Create InstallStateTool\ninstalls_path = Some user_dir]
    B -- no --> D{Shared/system dir?}
    D -- yes, tool not yet seen --> E[Create InstallStateTool\ninstalls_path = Some shared_dir]
    D -- yes, tool already seen --> F[Merge versions only\ninstalls_path unchanged]
    D -- no, plugin only --> G[Create InstallStateTool\ninstalls_path = None]

    C --> H[From InstallStateTool for BackendArg]
    E --> H
    F --> H
    G --> H

    H --> I[new_raw sets installs_path\n= dirs::INSTALLS default user path]
    I --> J{ist.installs_path Some?}
    J -- yes --> K[Override installs_path\nwith stored path]
    J -- no --> L[Keep default user path]

    K --> M[BackendArg.installs_path\n= actual on-disk path]
    L --> N[BackendArg.installs_path\n= default user path]

    style E fill:#90EE90
    style K fill:#90EE90
    style M fill:#90EE90

_{Last reviewed commit: "fix: failing rebuild..."}