Poetry: {cache-dir} placeholder not properly resolved in virtualenvs.path

[karthiknadig]

Problem

When querying poetry config virtualenvs.path, Poetry may return a path containing the {cache-dir} placeholder (e.g., {cache-dir}/virtualenvs). The extension doesn't properly resolve this placeholder.

Current Code

// poetryUtils.ts L157-164
const { stdout } = await exec(`"${poetry}" config virtualenvs.path`);
if (stdout) {
    const venvPath = stdout.trim();
    // Poetry might return the path with placeholders like {cache-dir}
    // If it doesn't start with / or C:\ etc., assume it's using default
    if (!path.isAbsolute(venvPath) || venvPath.includes('{')) {
        const home = getUserHomeDir();
        if (home) {
            poetryVirtualenvsPath = path.join(home, '.cache', 'pypoetry', 'virtualenvs');
        }
    }

Issue

1. When {cache-dir} is detected, the code falls back to a hardcoded path that's incorrect on Windows (see Poetry: Incorrect default virtualenvs path on Windows and macOS #1182)
2. The {cache-dir} placeholder should be properly resolved to Poetry's actual cache directory

PET Server Reference

The PET server properly resolves this in pet-poetry/src/config.rs:

fn resolve_virtualenvs_path(virtualenvs_path: &Path, cache_dir: &Option<PathBuf>) -> PathBuf {
    if virtualenvs_path
        .to_string_lossy()
        .to_lowercase()
        .contains("{cache-dir}")
    {
        if let Some(cache_dir) = &cache_dir {
            let virtualenvs_path = PathBuf::from(
                virtualenvs_path
                    .to_string_lossy()
                    .replace("{cache-dir}", cache_dir.to_string_lossy().as_ref()),
            );
            return virtualenvs_path;
        }
    }
    virtualenvs_path.to_path_buf()
}

Suggested Fix

1. Query Poetry's cache directory: poetry config cache-dir
2. Replace {cache-dir} in the virtualenvs path with the actual cache directory
3. If cache-dir query fails, use platform-specific defaults

async function resolveVirtualenvsPath(poetry: string, virtualenvsPath: string): Promise<string> {
    if (virtualenvsPath.includes('{cache-dir}')) {
        try {
            const { stdout } = await exec(`"${poetry}" config cache-dir`);
            const cacheDir = stdout.trim();
            return virtualenvsPath.replace('{cache-dir}', cacheDir);
        } catch {
            // Fall back to platform-specific default cache dir
            return virtualenvsPath.replace('{cache-dir}', getDefaultCacheDir());
        }
    }
    return virtualenvsPath;
}

Affected File

src/managers/poetry/poetryUtils.ts