Function expand_kernel_range 

pub fn expand_kernel_range(
    start: &str,
    end: &str,
    cli_label: &str,
    include_eol: bool,
) -> Result<Vec<String>>

Expand a kernel-version range to the list of stable / longterm releases that fall inside [start, end] inclusive.

Fetches kernel.org’s releases.json once via crate::fetch::cached_releases, filters to rows whose moniker is stable or longterm (matching the policy crate::fetch::fetch_latest_stable_version uses for “is this a production release we want to test against”), drops any version outside the inclusive interval, and returns the surviving versions sorted ascending by (major, minor, patch, rc) tuple. Empty result is a hard error — an empty range either reflects a typo (start/end don’t bracket any active series) or releases.json missing rows the operator expected, and silently iterating over zero kernels would mask both. The KernelId::Range doc comment promises “every release in the range” which a quiet no-op contradicts.

Range endpoints are NOT required to appear in releases.json — the interval is half-the-numeric, half-presence: 6.10..6.16 selects every stable release inside that span, regardless of whether 6.10 and 6.16 themselves are still listed (e.g. one has been pruned from active maintenance). This matches the inclusive-numeric-comparison semantics in crate::kernel_path::KernelId::validate and lets a range from an EOL series survive even after the endpoint version itself becomes unavailable.

Endpoint granularity is series-inclusive on BOTH ends: a 2-component MAJOR.MINOR endpoint names the whole series, so 6.11..6.14 includes every 6.14.N (not just 6.14.0). START is series-inclusive because its .0 is the series floor; END is widened to the series ceiling by range_bounds. An explicit-patch endpoint (6.14.2) is an exact bound — 6.11..6.14.2 stops at 6.14.2.

cli_label prefixes the kernel.org-fetch status line so the diagnostic matches the binary that triggered the lookup ("ktstr" vs "cargo ktstr").

When include_eol is set, the maintained set from releases.json is unioned with EOL stable series enumerated from the gregkh linux-stable mirror’s tags (crate::fetch::cached_stable_tags), then the highest patch of each (major, minor) series is taken across both sources (select_series_latest_in_range). Without it a series dropped from releases.json is silently absent — 6.11..6.14 collapses to just the 6.11 series if 6.12/6.13 are EOL. If the mirror tag list cannot be fetched, expansion proceeds against the active-release set alone with a warning; the empty-result error hints --include-eol only when it was not already set.

Pre-release filter: mainline and linux-next rows are excluded by the moniker filter; rc tags carrying a stable moniker would also be excluded but kernel.org publishes rcs under mainline, so the filter is double-coverage in practice. Operators who want to test against an rc spell it out as a single --kernel 6.16-rc3 rather than expecting the range expansion to surface it.