Contender is failing

[canercidam]

Problem 1

Using latest causes a potentially broken draft release to be used (v0.7.1) and the previous two versions seem to work:

• v0.6.0
• v0.7.0 (requires switching from -l to --forever)

Problem 2

Contender needs to start making requests when the target is available (e.g. when testing builder in QEMU VM). Otherwise the whole thing fails.

Problem 3

With v0.7.0, contender is complaining that some txs have failed. Maybe this is okay but it is worth an investigation. (Is 2/20 succeeded txs or failed?)

2026-01-12T15:43:17.694383Z  WARN some spam txs failed to send: 2 / 20
2026-01-12T15:43:18.697913Z  INFO preparing 20 spam payloads
2026-01-12T15:43:18.703072Z  INFO prepared 20 payloads
2026-01-12T15:43:19.708988Z  INFO [9] executed 20 spam tasks
2026-01-12T15:43:19.709032Z  INFO all spam txs sent successfully
2026-01-12T15:43:19.776020Z  INFO done. run_id: 1
2026-01-12T15:43:20.780478Z  INFO preparing 20 spam payloads
2026-01-12T15:43:20.782757Z  INFO prepared 20 payloads
2026-01-12T15:43:21.785788Z  INFO [0] executed 20 spam tasks
2026-01-12T15:43:21.785826Z  WARN some spam txs failed to send: 2 / 20
2026-01-12T15:43:22.789365Z  INFO preparing 20 spam payloads
2026-01-12T15:43:22.791690Z  INFO prepared 20 payloads
2026-01-12T15:43:23.796350Z  INFO [1] executed 20 spam tasks
2026-01-12T15:43:23.796384Z  INFO all spam txs sent successfully
2026-01-12T15:43:24.798971Z  INFO preparing 20 spam payloads
2026-01-12T15:43:24.801476Z  INFO prepared 20 payloads

[zeroXbrock]

re Problem 2:

Not sure how to solve this just yet.

The check we currently employ is just service.DependsOnHealthy and sometimes service.DependsOnRunning:

service := manifest.NewService("contender").
	WithImage("flashbots/contender").
	WithTag("0.7.2").
	WithArgs(args...).
	DependsOnHealthy("beacon")

if c.TargetChain == "op-geth" {
	service.DependsOnRunning("op-node")
}

• Is there a programmatic way to get the appropriate service name?
  • i.e. to map "op-geth" (targetChain) to "op-node"(target service)?
• Would DependsOnHealthy work to prevent contender from running before the node's ready?

[canercidam]

Reopening to track problem 2.

[zeroXbrock]

@canercidam any update on this?