The build-packages.yml run was failing for two compounding reasons, found by testing directly against vbatts/slackware:15.0 on the actual runner host: 1. The image ships neither git nor its HTTPS runtime libs, so actions/checkout failed immediately. 2. It's a minimal rootfs with none of the 'D' (development) series — no gcc, make, autoconf, pkg-config, curl, glib2, libcap, or fuse3 — contrary to setup-slackware-buildenv.sh's assumption that a "full" Slackware install already provides these. An earlier fix attempt hand-pinned git + its deps (nghttp2, brotli, cyrus-sasl) by exact file + SHA256 from the base 15.0 release directory. That drifted out of sync with the newer, patched curl slackpkg installs later in the same container — same shared library, two different builds, causing a runtime symbol lookup error. Both steps now resolve every package through slackpkg's own prioritized mirror instead, keeping the whole toolchain on one mutually consistent version set. Verified end-to-end (git ls-remote and curl both succeed over HTTPS against the real Gitea instance, full toolchain present) in a fresh vbatts/slackware:15.0 container. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>