---
page_id: wsd-yosys-check-errors-found-19ef2f15
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title: "Thread: Yosys check errors found"
slug: wsd-yosys-check-errors-found-19ef2f15
route: /evidence/i-information/questions/threads/yosys-check-errors-found
section: reference
access: public
summary: 7 Discord messages from ℹ️ - Information/⁉️-questions/threads/yosys-check-errors-found.md.
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tags: [discord, wafer-space, archive]
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---
# Thread: Yosys check errors found
Category: **ℹ️ - Information**
Parent channel: **#⁉️-questions**
Thread ID: `1440427510159638538`
Messages: **7**
## message-1440427510159638538
**2025-11-18T19:44:40.271+00:00 — LukeW (@_luke_w_)**
- Message ID: `1440427510159638538`
- Author ID: `803213471402688522`
- Nickname: LukeW
- User name: _luke_w_
- Type: `Default`
- Discord message: https://discord.com/channels/1361349522684510449/1440427510159638538/1440427510159638538
- Archive source: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11.json
- Archive source: https://discord.wafer.space/wafer-space/Information/questions/yosys-check-errors-found/2025-11/2025-11.json
**Content**
````text
I had this message, failing in stage `08-checker-yosyssynthchecks`:
```
39 Yosys check errors found.
```
Grepping for `error` in my yosys synthesis log didn't show any likely-looking errors. I eventually realised that 39 was exactly the number of bidi pad data pins I'd not yet bothered to connect (early hacking!) so my issue is solved, but next time I get this message, how do I find the actual errors? Is `yosys-synthesis.log` the wrong place to look?
````
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## message-1440439686526144552
**2025-11-18T20:33:03.343+00:00 — aedancullen**
- Message ID: `1440439686526144552`
- Author ID: `537091611323007003`
- Nickname: aedancullen
- User name: aedancullen
- Type: `Default`
- Edited: 2025-11-18T20:42:12.56+00:00
- Discord message: https://discord.com/channels/1361349522684510449/1440427510159638538/1440439686526144552
- Archive source: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11.json
- Archive source: https://discord.wafer.space/wafer-space/Information/questions/yosys-check-errors-found/2025-11/2025-11.json
**Content**
```text
They are buried in `yosys-synthesis.log` (grep for "Executing CHECK pass") and also seem to appear separately in `reports/pre_synth_chk.rpt` (in the same yosys-synthesis step of the flow)
It is definitely confusing that the 08-checker step produces the error but isn't the producer of that file
```
**Reactions**
- Resolved media URL: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11_media/1f44d-27259.svg
- Resolved media URL: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11_media/a2f98861602ee8229f4eb87d5c25d1b1-5FBF4.png
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---
## message-1440478400174227487
**2025-11-18T23:06:53.396+00:00 — LukeW (@_luke_w_)**
- Message ID: `1440478400174227487`
- Author ID: `803213471402688522`
- Nickname: LukeW
- User name: _luke_w_
- Type: `Default`
- Discord message: https://discord.com/channels/1361349522684510449/1440427510159638538/1440478400174227487
- Archive source: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11.json
- Archive source: https://discord.wafer.space/wafer-space/Information/questions/yosys-check-errors-found/2025-11/2025-11.json
**Content**
```text
Weird, I did see the CHECK output but nothing obvious under there. Anyway thanks, I know where to look next time. Familiar name by the way 😅
```
**Reactions**
- Resolved media URL: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11_media/1f642-83E8A.svg
- Resolved media URL: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11_media/fc1bc9aef8b4b153a5765fb1d45f5241-983A5.png
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---
## message-1440533456940437708
**2025-11-19T02:45:39.952+00:00 — LukeW (@_luke_w_)**
- Message ID: `1440533456940437708`
- Author ID: `803213471402688522`
- Nickname: LukeW
- User name: _luke_w_
- Type: `Default`
- Discord message: https://discord.com/channels/1361349522684510449/1440427510159638538/1440533456940437708
- Archive source: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11.json
- Archive source: https://discord.wafer.space/wafer-space/Information/questions/yosys-check-errors-found/2025-11/2025-11.json
**Content**
````text
had to dig in a little more because I have a check.rpt saying:
```
Found and reported 0 problems.
```
And a state_out.json saying:
```
"synthesis__check_error__count": 1
```
Seems like the actual source for that log lint is here:
https://github.com/librelane/librelane/blob/2bf4f4a399da9d41fbef24814cd7946bf9692ead/librelane/steps/pyosys.py#L50-L92
````
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---
## message-1440533779826348216
**2025-11-19T02:46:56.934+00:00 — LukeW (@_luke_w_)**
- Message ID: `1440533779826348216`
- Author ID: `803213471402688522`
- Nickname: LukeW
- User name: _luke_w_
- Type: `Default`
- Discord message: https://discord.com/channels/1361349522684510449/1440427510159638538/1440533779826348216
- Archive source: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11.json
- Archive source: https://discord.wafer.space/wafer-space/Information/questions/yosys-check-errors-found/2025-11/2025-11.json
**Content**
````text
which got me the correct error (which should really be fatal in yosys!)
```
Warning: Wire $paramod$053944574b759a0e3f2ebe9134306bd1be3bd197\twowire_dtm_core.\ndtmresetreq is used but has no driver.
```
````
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---
## message-1441578023856898190
**2025-11-21T23:56:24.112+00:00 — Tim 'mithro' Ansell (@mithro_)**
- Message ID: `1441578023856898190`
- Author ID: `169786952432746498`
- Nickname: Tim 'mithro' Ansell
- User name: mithro_
- Type: `Default`
- Discord message: https://discord.com/channels/1361349522684510449/1440427510159638538/1441578023856898190
- Archive source: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11.json
- Archive source: https://discord.wafer.space/wafer-space/Information/questions/yosys-check-errors-found/2025-11/2025-11.json
**Content**
```text
@LukeW - Did you end up getting this one solved?
```
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---
## message-1441588410002313468
**2025-11-22T00:37:40.362+00:00 — LukeW (@_luke_w_)**
- Message ID: `1441588410002313468`
- Author ID: `803213471402688522`
- Nickname: LukeW
- User name: _luke_w_
- Type: `Default`
- Discord message: https://discord.com/channels/1361349522684510449/1440427510159638538/1441588410002313468
- Archive source: https://discord.wafer.space/wafer-space/%E2%84%B9%EF%B8%8F%20-%20Information/%E2%81%89%EF%B8%8F-questions/yosys-check-errors-found/2025-11/2025-11.json
- Archive source: https://discord.wafer.space/wafer-space/Information/questions/yosys-check-errors-found/2025-11/2025-11.json
**Content**
```text
yep, I know the things to grep the log for now 🙂
```
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