cli-raw-libgit2-error-doubling

Answer

Root cause (GAP-029). In hilo-cli/src/commands/backend.rs, the mount command's git path (--type git --url <url>) surfaced the libgit2 failure through an anyhow chain that kept git2::Error both inlined into the message text and attached as the source — e.g. anyhow::Error::new(e).context(format!("... {e}")) or a .context(...) on a map_err(anyhow::Error::new). {:?} then renders the raw git2 error twice:

error: failed to mount git backend from URL 'git://nonexistent.invalid/...': failed to resolve address for nonexistent.invalid: Name or service not known; class=Net (12)
Caused by:
    failed to resolve address for nonexistent.invalid: Name or service not known; class=Net (12)

Fix. map_err into a single anyhow! message — the inline {e} flattens the chain (no source), so {:?} prints exactly one line, with an actionable hint (check URL/credentials). Canonical patch for hilo-cli/src/commands/backend.rs:

use anyhow::{anyhow, Context, Result};

/// Single-message wrapper: inlines the git2 error via `{e}` so no source
/// chain is attached, then appends an actionable hint.
fn git_mount_err(url: &str, e: git2::Error) -> anyhow::Error {
    anyhow!(
        "failed to mount git backend from URL '{url}': {e} \
         (check that the URL is reachable and your credentials are valid)"
    )
}

fn mount_git(url: &str, dest: &Path) -> Result<()> {
    let repo = git2::Repository::clone(url, dest)
        .map_err(|e| git_mount_err(url, e))?; // was: .map_err(anyhow::Error::new).context(format!("... {e}"))
    // ... register repo ...
    Ok(())
}

Notes: - Do not add .context(...) on top afterward — that re-creates a source layer. - No information is lost: Display for git2::Error already includes class/code (class=Net (12)), so the single message is as diagnostic as before, minus the duplicated dump. - The hint wording should be adjusted to what the CLI can actually act on (e.g. "check the URL is reachable and your credentials are valid" for SSH/HTTPS auth failures).

Process fixes (secondary): - Exit codes: the hunter premise that the command "exited 0" was wrong — it already exits 1. Verify exit codes live ($? after running the binary directly, not through a pipeline) before claiming them in a report. - Evaluator quirk: gitreins tier-2 fails with a DeepSeek 400 while max_output_tokens is 2M; DeepSeek caps at 393216, so drop it to 131072 when judging with DeepSeek.