fix: canonicalize prefix paths before comparison to handle symlinked venvs (Fixes #358)

[karthiknadig]

Fix false positive "Prefix is incorrect" telemetry warning when a venv prefix path is a symlink.

• Canonicalize both discovered and resolved prefix paths before comparison so symlinks to the same directory are treated as equal
• Wrap canonicalized paths in norm_case() to handle Windows \\?\ UNC prefix from canonicalize
• Fall back to original path if canonicalization fails (e.g., path no longer exists)

Fixes #358

[github-actions]

Test Coverage Report (Linux)

Metric	Value
Current Coverage	59.1%
Base Branch Coverage	58.3%
Delta	.8% ✅

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Coverage increased! Great work!

[github-actions]

Performance Report (Linux) ✅

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta	Change
Server Startup	1ms	1ms	1ms	0ms	0%
Full Refresh	71ms	557ms	78ms	-7ms	0%

Results based on 10 iterations. P50 = median, P95 = 95th percentile.

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Legend

• 🚀 Significant speedup (>100ms faster)
• ✅ Faster than baseline
• ➖ No significant change
• 🔺 Slower than baseline (>100ms)
• ⚠️ Significant slowdown (>500ms)

[github-actions]

Performance Report (Windows) ✅

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta	Change
Server Startup	9ms	12ms	10ms	-1ms	-10%
Full Refresh	159ms	1268ms	181ms	-22ms	-12.2%

Results based on 10 iterations. P50 = median, P95 = 95th percentile.

---

Legend

• 🚀 Significant speedup (>100ms faster)
• ✅ Faster than baseline
• ➖ No significant change
• 🔺 Slower than baseline (>100ms)
• ⚠️ Significant slowdown (>500ms)

[github-actions]

Test Coverage Report (Windows)

Metric	Value
Current Coverage	55.32%
Base Branch Coverage	54.58%
Delta	0.74% ✅

---

Coverage increased! Great work!

[Copilot]

Pull request overview

This PR fixes a false positive "Prefix is incorrect" telemetry warning that occurs when a venv's prefix path is a symlink. The issue arose because the telemetry validation code compared prefix paths directly without resolving symlinks, causing symlinked paths to be flagged as incorrect even though they point to the same directory.

Changes:

• Canonicalize both discovered and resolved prefix paths before comparison to resolve symlinks
• Wrap canonicalized paths in norm_case() to handle Windows UNC prefix (\\?\) added by canonicalize
• Use fallback to original path if canonicalization fails (e.g., path no longer exists)

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

crates/pet-telemetry/src/lib.rs:53

• The canonicalization approach in the telemetry module differs from the pattern used in crates/pet-env-var-path/src/lib.rs where Unix-specific canonicalization is applied selectively. In normalize_search_path, canonicalize is only called on Unix (to handle merged-usr symlinks) but not on Windows (to preserve junction tracking for tools like Scoop). Here, canonicalize is called on both platforms. While wrapping with norm_case handles the Windows UNC prefix issue, consider documenting why this approach is correct for prefix paths specifically, or whether Windows junction paths in venv prefixes could cause similar issues to those mentioned in issue #187 for Scoop.

    let invalid_prefix = if let Some(ref env_prefix) = env.prefix {
        let resolved_prefix = resolved.prefix.clone()?;
        // Canonicalize both paths to handle symlinks — a venv prefix like
        // /usr/local/venvs/myvenv may be a symlink to /usr/local/venvs/versioned/myvenv-1.0.51,
        // and sys.prefix returns the resolved target. Without this, the comparison
        // produces a false positive "Prefix is incorrect" warning. (See #358)
        // Wrap in norm_case to handle Windows UNC prefix (`\\?\`) from canonicalize.
        let env_canonical =
            norm_case(std::fs::canonicalize(env_prefix).unwrap_or(env_prefix.clone()));
        let resolved_canonical =
            norm_case(std::fs::canonicalize(&resolved_prefix).unwrap_or(resolved_prefix));
        env_canonical != resolved_canonical

[Copilot]

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

[github-actions]

Performance Report (macOS)

Metric	PR (P50)	PR (P95)	Baseline (P50)	Delta
Server Startup	55ms	499ms	48ms	7ms
Full Refresh	121ms	26419ms	93ms	28ms

Results based on 10 iterations. P50 = median, P95 = 95th percentile.

---

Legend

• 🚀 Significant speedup (>100ms faster)
• ✅ Faster than baseline
• ➖ No significant change
• 🔺 Slower than baseline (>100ms)
• ⚠️ Significant slowdown (>500ms)