A synthesis change wired unused flip-flop inputs to 0 and the place-and-route tool then failed: since one commit, synth_ecp5 writes TRELLIS_FF cells with unused CE and M inputs connected to constant 0, and nextpnr-ecp5 then fails in FF packing with an internal check failure. A one-line change in one tool broke the next tool in the chain.
Recurring agent failure issue in yosys (YosysHQ)
What engineers report
A recurring agent failure problem in yosys (YosysHQ) that mostly hits the mechanical designer.
Failure pattern: validation / failure
Analyst note
From the Grok pain-radar digests, Nov 8-9 2026 (Nov 8 8:41 AM ET through Nov 9 6:41 AM ET digests plus the Haitch editions). Verified live 2026-11-09: issue/PR read; title and state confirmed.
What it costs a team
Modeled annual cost
$30,000
For a team of 5
Prototype delay
3 days
Modeled schedule slip per occurrence
Time lost
240 min
Per engineer per month, about 1 incidents
How the cost is modeled
240 min/month × 5 engineers × 12 months = 240 hours × $125/hour = $30,000
A modeled estimate with medium confidence. Swap in your own team size and loaded rate to size it for your team.
Engineering tools that address it
No engineering tool profile lists this error yet. Browse tools that connect to yosys (YosysHQ).
Evidence
More recurring errors in yosys (YosysHQ)
Sourced from public community reports. Costs and delays are modeled estimates, not measurements. Know a better source or a fix? Tell us at hello@productflo.io.