Mirrors and cache

Every Keru build is a network operation. Two mechanisms keep that sane and reproducible: a mirror-first download policy, and a well-defined cache on disk.

Download order

1. SOURCE_MIRROR — tried first when set; run a mirror of source tarballs and point it here.
2. Upstream — the canonical source URL from the recipe. Used when no mirror is set or the mirror lacks a file.
Verification at every step. A file that doesn't match its checksum is dropped, and the next source in line is tried. Tampered files never reach a build.

The cache layout

/var/cache/kama/        # CACHEDIR (set CACHEDIR=/path to relocate)
├── dl/                  # downloaded tarballs, one per package
├── src/                 # extracted source (per package dir)
└── stage/               # staged installs before they commit to $ROOT

Dir	Everything	Purpose
`dl`	Downloads	Already-downloaded archives are reused, never re-fetched.
`src`	Extracted	Extraction is skipped when the checked-out source is present.
`stage`	Staged builds	Progress survives a failed build; re-running continues.

Working offline, or your own mirror

# warm the cache once, then build with the network down
SOURCE_MIRROR=https://mirror.example.org kama fetch busybox
...
CACHEDIR=/var/cache/kama kama make busybox   # no network needed

Run a mirror yourself and point SOURCE_MIRROR at it. The layout mirrors dl/; the fetch layer treats it as a read-mostly source of truth.

Cleanup

rm -rf /var/cache/kama/src/* — free extracted source (re-extracts on next build).
rm -rf /var/cache/kama/dl/* — dump downloads (re-fetches next time).
rm -rf /var/cache/kama/stage/* — discard staged builds.

A corrupt cache is the #1 source of confusing fetch errors. When in doubt, clear the relevant dir — downloads verify anyway, so you lose nothing but time.

← kama usage · Troubleshooting