fix(bootstrap): preserve argv[0] for shim dispatch

[tak848]

Summary

mise generate bootstrap currently emits:

exec "$MISE_INSTALL_PATH" "$@"

That drops the original invocation name.

When the generated bootstrap is used through a shim symlink such as claude -> /path/to/mise, the final mise process sees the cached binary path as argv[0] instead of claude, so shim dispatch breaks.

Direct usage of the generated bootstrap as mise itself should remain unchanged.

That direct usage is already documented and expected to work, for example:

mise generate bootstrap >./bin/mise
chmod +x ./bin/mise
PATH="./bin:$PATH" mise install

This change switches the generated exec line to:

exec -a "$0" "$MISE_INSTALL_PATH" "$@"

That preserves the shim name when invoked via symlink while still behaving like normal mise when the generated script itself is installed as mise.

Test plan

• ./e2e/run_test generate/test_generate_bootstrap
• verify direct ./bin/mise version still works
• verify generated bootstrap output contains exec -a "$0"
• verify localized bootstrap output still works

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a critical issue in mise's bootstrap generation where the original invocation name (argv[0]) was dropped, causing shim dispatch to fail when mise was called through a symlink. The core change updates the generated bootstrap script to explicitly preserve argv[0] using exec -a "$0", ensuring correct behavior for both direct and symlinked invocations.

Highlights

• Bootstrap script exec command: Modified the mise generate bootstrap output to use exec -a "$0" "$MISE_INSTALL_PATH" "$@" instead of exec "$MISE_INSTALL_PATH" "$@".
• Shim dispatch fix: This change preserves the original invocation name (argv[0]), resolving an issue where shim dispatch would break when mise was invoked via a symlink.
• Test coverage: Added new assertions to the e2e/generate/test_generate_bootstrap script to verify the presence of the exec -a "$0" command in generated bootstrap scripts.

Changelog

• e2e/generate/test_generate_bootstrap
  • Added assertions to check for the exec -a "$0" command in the generated bootstrap scripts.
• src/cli/generate/bootstrap.rs
  • Changed the exec command in the generated bootstrap script from exec "$MISE_INSTALL_PATH" "$@" to exec -a "$0" "$MISE_INSTALL_PATH" "$@".

Activity

• Verified that direct usage of ./bin/mise version continues to function as expected.
• Confirmed that the generated bootstrap output now correctly contains exec -a "$0".
• Ensured that localized bootstrap output still works.
• Executed the e2e/run_test generate/test_generate_bootstrap test suite.

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[gemini-code-assist]

Code Review

This pull request addresses an issue where the original invocation name (argv[0]) was not preserved when using a generated bootstrap script as a symlink. The fix is correct for the file changed. However, the same issue exists in other parts of the codebase that generate scripts. I've added a review comment with suggestions to fix these related issues for consistency, as I am unable to comment on files not included in this pull request's diff.

[gemini-code-assist]

While this change correctly fixes the issue for the bootstrap script, the same problem exists in other script-generating commands. To ensure consistent behavior and fully resolve the argv[0] preservation issue, similar changes are needed in other files.

Since I can only comment on changed files, I'm leaving this feedback here. Please consider applying fixes to the following:

1. src/cli/generate/tool_stub.rs:
   In the wrap_with_bootstrap function, the exec call does not preserve argv[0]. It should be changed from:

   exec "$MISE_BIN" tool-stub "$0" "$@"

   to:

   exec -a "$0" "$MISE_BIN" tool-stub "$0" "$@"

2. src/cli/generate/task_stubs.rs:
   The generated script in the generate function uses #!/bin/sh and an exec call that doesn't preserve argv[0]. This should be updated to use bash and exec -a.
   Change from:

   #!/bin/sh
   exec {mise_bin} run {display_name} "$@"

   to:

   #!/usr/bin/env bash
   exec -a "$0" {mise_bin} run {display_name} "$@"

[tak848]

This is out of scope for this PR.

This change is limited to mise generate bootstrap. Other generators should be evaluated separately.

[tak848]

Correction: this is not the same issue.

This PR is limited to mise generate bootstrap, where preserving argv[0] is required for shim dispatch.

tool_stub.rs passes the original path explicitly to tool-stub, and task_stubs.rs invokes mise run {display_name} directly, so they do not depend on argv[0] in the same way.

[greptile-apps]

Greptile Summary

This PR fixes a one-liner in the generated bootstrap script so that argv[0] is preserved when the script is invoked via a shim symlink (e.g. claude -> /path/to/bootstrap). The change swaps exec "$MISE_INSTALL_PATH" "$@" for exec -a "$0" "$MISE_INSTALL_PATH" "$@", which is the standard POSIX-adjacent idiom for forwarding the caller's name through a shell wrapper.

Key points:

• Correctness – exec -a name is supported by bash (the shebang requires #!/usr/bin/env bash) including macOS's default bash 3.2, so there are no portability regressions.
• Backward compatibility – when the script is invoked directly as ./bin/mise, $0 equals ./bin/mise, so mise still sees itself as mise and behaves identically to before.
• Test coverage – both the regular (-w) and localized (-l -w) bootstrap paths now assert the new exec -a "$0" line is present in the generated file; SC2016 suppression is correctly applied to avoid false shellcheck warnings on the single-quoted $0.

Confidence Score: 5/5

• This PR is safe to merge — the change is a one-line, well-understood shell idiom with no side-effects on existing usage.
• The fix is minimal and targeted, uses a well-supported bash built-in flag (exec -a), preserves all existing behaviour for direct invocations, and is covered by updated e2e tests for both bootstrap modes.
• No files require special attention.

Important Files Changed

Filename	Overview
src/cli/generate/bootstrap.rs	Single-line fix replacing exec "$MISE_INSTALL_PATH" "$@" with exec -a "$0" "$MISE_INSTALL_PATH" "$@" to preserve argv[0] through shim dispatch; change is minimal and correct.
e2e/generate/test_generate_bootstrap	Test updated to assert the new exec -a "$0" line appears in the generated bootstrap for both regular and localized modes; SC2016 suppression is appropriate for single-quoted shell variables.

Sequence Diagram

sequenceDiagram
    participant User as User / Shell
    participant Symlink as claude (symlink)
    participant Bootstrap as Bootstrap Script ($0="claude")
    participant Mise as mise binary

    Note over User,Mise: Shim dispatch via symlink (new behaviour)
    User->>Symlink: invoke claude
    Symlink->>Bootstrap: exec bootstrap ($0 = "claude")
    Bootstrap->>Bootstrap: __mise_bootstrap() — install if needed
    Bootstrap->>Mise: exec -a "claude" $MISE_INSTALL_PATH "$@"
    Note right of Mise: argv[0] == "claude" → shim dispatch works ✓

    Note over User,Mise: Direct invocation (unchanged behaviour)
    User->>Bootstrap: ./bin/mise install ($0 = "./bin/mise")
    Bootstrap->>Bootstrap: __mise_bootstrap() — install if needed
    Bootstrap->>Mise: exec -a "./bin/mise" $MISE_INSTALL_PATH "$@"
    Note right of Mise: argv[0] == "./bin/mise" → normal mise ✓

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[tak848]

coverage-7 failure is unrelated to this PR — caused by Java EA version bump (26 → 27). Fix is tracked in #8634

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Preserve absolute argv0 when re-executing bootstrap binary

Using exec -a "$0" "$MISE_INSTALL_PATH" "$@" forwards relative invocation names (for example ./bin/mise) into argv[0]. On Linux, activate intentionally uses ARGV0 as the executable path (src/cli/activate.rs), so eval "$(./bin/mise activate bash)" now emits hooks that call ./bin/mise and those hooks fail after changing directories away from the project root. Before this change, argv[0] was the absolute install path, so the generated activation hooks remained valid across directories.

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