Found by testing a real enable/disable cycle (art, fjb, gift-card):
1. compose_gen always swapped build->image, so a never-built challenge
produced 'pull access denied for services-<name>'. Now it only reuses
the image when it exists locally, otherwise keeps build: so
'docker compose up --build' builds it.
2. Canonical templates use 'build: context: .' (written for the shared
services/ tree). In the per-team compose that resolves to the team dir
which has no Dockerfile -> 'failed to read dockerfile'. The renderer
now rewrites the main service's context to ./<name>.
3. Teams created before the XVI/XVII import had no xvi/xvii subpackages
under their local challenges/ dir, so the regenerated receiver main.py
crash-looped on import. gen_receiver_main now mirrors ALL shared
checkers (native + xvi + xvii) into every team receiver on each sync.
4. systemd Environment= keys can't contain hyphens, so
CHALLENGE_PORT_GIFT-CARD was silently dropped. Keys are now
normalized to underscores on both the writer and reader side.
5. Several checkers called 'docker exec' with no timeout; against a
container with accumulated chall.py zombies that blocks forever and
stalls the whole SLA loop. Added mandatory timeouts (Phew, Sheesh,
Carbeat, Poke, Warmup).
Also: enabling a challenge now copies its source tree into each team's
services/ dir (team dirs only held challenges enabled at create_team
time), and the XVII checkers were rewritten to be protocol-aware
(gift-card/gift-voucher are socat TCP, not HTTP) with strict timeouts.
MythEclipse